Try to use azure_client_id when authenticating

[equinor-ruaj]

When authenticating, first try to use the env variable AZURE_CLIENT_ID

If it is not set: use the default sumo-client (as today)
If it is set:
- Check that authentication works: it could fail if the referenced app does not have access to sumo-core
- If authentication fails because the client is unknown:
- put an entry in the Sumo messagelog: "Application is not registered" or something. Also include the AZURE_CLIENT_ID somewhere.
- fall back to the default Sumo client
- If authentication works: continue as normal