Session needs a user id field, and SessionStore needs ability to invalidate/modify sessions by user id

### Version

* vert.x core: 4.0-SNAPSHOT
* vert.x auth: 4.0-SNAPSHOT

### Context

For security, Vertx needs the ability to invalidate all sessions for a given user id, and to write a given key/value pair to the data for all sessions with a given user id (to allow permissions to be granted or revoked instantly across all sessions). This should work across either a local session store or a clustered session store.

Currently there is no way to associate a user id (e.g. an email address) with a session, beyond simply storing the user id as a custom key/value pair in the session data. However, the session data is not indexed across all sessions, which makes it impossible to find all sessions that are associated with a given user id.

This means that it is currently not possible to forcibly log a user out from all sessions based on user id. It is also not possible to grant or revoke a permission to/from all sessions for the user, unless each session is constantly querying a shared map, which would require a database query in the clustered case, potentially for every request, rather than simply relying on cached permissions in the session store.

The needed methods would be:

* `void Session.setUserId(String userId)`
* `String Session.getUserId()`
* `int SessionStore.invalidateAllSessionsWithUserId(String userId)` -- maybe return the number of invalidated sessions
* `void SessionStore.putForAllSessionsWithUserId(String userId, String key, Object value)`

Then the user would set the user id in a session after the user authenticates for the first time. For OAuth2, this could be done automatically by fetching the userInfo via OpenID Connect after OAuth2 connects (the OIDC data often or usually contains the email address, or some other unique identifier). The OIDC data could be automatically cached in the session once it is fetched.