= Added iss parameter to OAuth 2.0/OpenID Connect Authentication Response

RFC 9207 OAuth 2.0 Authorization Server Issuer Identification specification adds the parameter `iss` in the OAuth 2.0/OpenID Connect Authentication Response for realizing secure authorization responses.

In past releases, we did not have this parameter, but now {project_name} adds this parameter by default, as required by the specification.

However, some OpenID Connect / OAuth2 adapters, and especially older {project_name} adapters, may have issues with this new parameter.

For example, the parameter will be always present in the browser URL after successful authentication to the client application.
In these cases, it may be useful to disable adding the `iss` parameter to the authentication response. This can be done
for the particular client in the {project_name} Admin console, in client details in the section with `OpenID Connect Compatibility Modes`,
described in <<_compatibility_with_older_adapters>>. Dedicated `Exclude Issuer From Authentication Response` switch exists,
which can be turned on to prevent adding the `iss` parameter to the authentication response.

= Wildcard characters handling

JPA allows wildcards `%` and `_` when searching, while other providers like LDAP allow only `*`.
As `*` is a natural wildcard character in LDAP, it works in all places, while with JPA it only
worked at the beginning and the end of the search string. Starting with this release the only
wildcard character is `*` which work consistently across all providers in all places in the search
string. All special characters in a specific provider like `%` and `_` for JPA are escaped. For exact
search, with added quotes e.g. `"w*ord"`, the behavior remains the same as in previous releases.

= Language files for themes default to UTF-8 encoding

This release now follows the standard mechanisms of Java and later, which assumes resource bundle files to be encoded in UTF-8.

Previous versions of Keycloak supported specifying the encoding in the first line with a comment like `# encoding: UTF-8`, which is no longer supported and is ignored.

Message properties files for themes are now read in UTF-8 encoding, with an automatic fallback to ISO-8859-1 encoding.
If you are using a different encoding, convert the files to UTF-8.

= Changes to the value format of claims mapped by the realm and client role mappers

Before this release, both realm (`User Realm Role`) and client (`User Client Role`) protocol mappers
were mapping a stringfied JSON array when the `Multivalued` setting was disabled.

However, the `Multivalued` setting indicates whether the claim should be mapped as a list or, if disabled, only a single value
from the same list of values.

In this release, the role and client mappers now map to a single value from the effective roles of a user when
they are marked as single-valued (`Multivalued` disabled).

= Changes to password fields in Login UI

In this version we want to introduce a toggle to hide/show password inputs.

.Affected pages:
- login.ftl
- login-password.ftl
- login-update-password.ftl
- register.ftl
- register-user-profile.ftl

In general all `<input type="password" name="password" />` are encapsulated within a div now. The input element is followed by a button which toggles the visibility of the password input.

Old code example:
[source,html]
----
<input type="password" id="password" name="password" autocomplete="current-password" style="display:none;"/>
----

New code example:
[source,html]
----
<div class="${properties.kcInputGroup!}">
    <input type="password" id="password" name="password" autocomplete="current-password" style="display:none;"/>
    <button class="pf-c-button pf-m-control" type="button" aria-label="${msg('showPassword')}"
            aria-controls="password" data-password-toggle
            data-label-show="${msg('showPassword')}" data-label-hide="${msg('hidePassword')}">
        <i class="fa fa-eye" aria-hidden="true"></i>
    </button>
</div>
----

= Default Keycloak CR Hostname

When running on OpenShift, with ingress enabled, and with the spec.ingress.classname set to openshift-default, you may leave the spec.hostname.hostname unpopulated in the Keycloak CR.
The operator will assign a default hostname to the stored version of the CR similar to what would be created by an OpenShift Route without an explicit host - that is ingress-namespace.appsDomain
If the appsDomain changes, or should you need a different hostname for any reason, then update the Keycloak CR.

= The deprecated `auto-build` CLI option was removed

The `auto-build` CLI option has been marked as deprecated for a long time.
In this release, it was completely removed, and it is no longer supported.

When executing the `start` command, the server is automatically built based on the configuration.
In order to prevent this behavior, set the `--optimized` flag.


= kc.sh and shell metacharacters

The kc.sh no longer uses an additional shell eval on parameters and the environment variables JAVA_OPTS_APPEND and JAVA_ADD_OPENS, thus the continued use of double escaping/quoting will result in the parameter being misunderstood.  For example instead of 

```
bin/kc.sh start --db postgres --db-username keycloak --db-url "\"jdbc:postgresql://localhost:5432/keycloak?ssl=false&connectTimeout=30\"" --db-password keycloak --hostname localhost
```

Use a single escape:

```
bin/kc.sh start --db postgres --db-username keycloak --db-url "jdbc:postgresql://localhost:5432/keycloak?ssl=false&connectTimeout=30" --db-password keycloak --hostname localhost
```

= Removed RegistrationProfile form action

The form action `RegistrationProfile` (displayed in the UI of authentication flows as `Profile Validation`) was removed from the codebase and also from all authentication flows. By default, it was in
the built-in registration flow of every realm. The validation of user attributes as well as creation of the user including all that user's attributes is handled by `RegistrationUserCreation` form action and
hence `RegistrationProfile` is not needed anymore. There is usually no further action needed in relation to this change, unless you used `RegistrationProfile` class in your own providers.

= Deprecated methods from data providers and models

* `RealmModel#getTopLevelGroupsStream()` and overloaded methods are now deprecated

= `GroupProvider` changes

A new method has been added to allow for searching and paging through top level groups.
If you implement this interface you will need to implement the following method:
[source,java]
----
Stream<GroupModel> getTopLevelGroupsStream(RealmModel realm,
                                           String search,
                                           Boolean exact,
                                           Integer firstResult,
                                           Integer maxResults)
----

= `GroupRepresentation` changes

* new field `subGroupCount` added to inform client how many subgroups are on any given group
* `subGroups` list is now only populated on queries that request hierarchy data
  * This field is populated from the "bottom up" so can't be relied on for getting all subgroups for a group. Use a `GroupProvider` or request the subgroups from `GET {keycloak server}/realms/{realm}/groups/{group_id}/children`

= New endpoint for Group Admin API

Endpoint `GET {keycloak server}/realms/{realm}/groups/{group_id}/children` added as a way to get subgroups of specific groups that support pagination