[FIXES #2408] SSO - Supported OpenID services

[afabiani]

The current PR addresses few issues mainly related to the refreshToken endpoint:

1. The main issue is due to the fact that if the current condition is met if ((expiresIn == null || fiveMinutesFromNow.after(expiresIn)) && refreshToken != null), i.e. the refreshToken is not expired yet, the sessionToken sent back will be NULL resulting in an 204: empty response causing the client to lose the current accessToken
2. The cache bean of the OIDC has a wrong name causing a context exception when trying to retrieve it from a new thread
3. Generally speaking the code checks only for accessToken nullability but consider it valid in the case it's empty, and this is an error and must be threated as an error.
4. The doRefresh method does not send the client_id to the IDP Refresh Endpoint, and this is can cause issues for strict compliant providers like Microsoft Azure