✨ [ENH] Have a self-manager role

[CChemin]

We need a role allowing users to manage themself.
What is itself ? If the user username matches a username in a realm it may be the same user but this user surely belongs to only one realm. When we add the right we scope it by realm/userstorage : self-manager-{realm}-{userstorage}
Maybe we want to scope by default an authentication method to a realm but we cannot manage multiple oidc configuration for now so we match all user coming from oidc to a realm while we should be able to configure several realm with oidc self-manager.
With the role added the user should be able to change values like its password but do we want it to be able to change other things like its name ?