Add subGroup as managed properties

[gdelbos]

What this PR does / why we need it:

Currently, only the groups attribute is managed. However, it can be interesting to allow the subGroups to be managed in the same way. This will allow the usage of multiple file containing specific subGroup configuration.

For instance, you can have a federation that is retrieving groups from an LDAP directory. Some on those groups must be updated to provided some specific roles. However, for lisibility, you want the groups from LDAP to be subgroups of a global container group. Additionaly, for maintenance purpose, you prefer to have one configuration file per LDAP group.

File 1:

{
  "realm": "my-realm",
  "groups": [
    {
      "name": "LDAPSync",
      "path": "/LDAPSync",
      "subGroups": [
        {
          "name": "GROUP_1",
          "path": "/LDAPSync/GROUP_1",
          "subGroups": [],
          "realmRoles": [
            "user"
          ],
          "clientRoles": {
            "my-user-service": [
              "user_read",
              "user_search"
            ]
          }
        }
      ]
    }
  ]
}

File 2:

{
  "realm": "my-realm",
  "groups": [
    {
      "name": "LDAPSync",
      "path": "/LDAPSync",
      "subGroups": [
        {
          "name": "GROUP_2",
          "path": "/LDAPSync/GROUP_2",
          "subGroups": [],
          "realmRoles": [
            "admin"
          ],
          "clientRoles": {
            "my-user-service": [
              "user_read",
              "user_search",
              "user_update",
              "user_create",
              "user_delete"
            ]
          }
        }
      ]
    }
  ]
}

After the import of those two file, with the modification of the subGroup managed propertie value, we will have 1 container group (LDAPSync) containing two sub group: GROUP_1 and GROUP_2

PR Readiness Checklist:

Complete these before marking the PR as ready to review:

• the CHANGELOG.md release notes have been updated to reflect any significant (and particularly user-facing) changes introduced by this PR

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

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