Include info about calling user in logs

[nilsgstrabo]

We should include info about the user/SP/anonymous that performs a request, for example in a new field "user"
This info can be extracted from the JWT token, and we should try the following claims in order: upn -> oid -> sub (always present). Log which claim was used in "user_claim". Perhaps there are other claims of interest, like idtyp?

This information is useful when debugging issues reported by users. We can easily filter logs related to a specific user. IT is also required in order to investigate security related events.

We should also validate the bearer token instead of just trusting the authnz of Kubernetes. No need to forward the request if token is not valid.

DoD
In log entry, the user (username) can be identified.
Log: ContainerLog (from radix-api, radix-log-api, vulnerability-scan-api, servicenow-api)