Add integration tests for table sessions

[adutra]

We should add integration tests for table sessions. But there is no REST server making use of them that we could use in tests: Nessie and Polaris do not allow vending OAuth2 properties in a LoadTableResult. We'll probably need to mock the server.

We should test:

• "legacy" properties:
  • token: should be honored, but with a warning (against OAuth2 standards)
  • forbidden properties like credential should be ignored with a warning
  • typed tokens, i.e. properties starting with urn:ietf:params:oauth:token-type:: should be ignored with a warning
• "new" properties
  • rest.auth.oauth2.scope to validate that vending OAuth2 scopes work.
  • forbidden properties: should be ignored with a warning
  • other properties: we can test them as well but there is little value in "vending" them.