docs: add other required fields to user setup for clustered

[david-rusnak]

Hey team! A customer attempted to use azure docs during clustered set up and ran into an issue with the current code example for setting azure users in the appInstance. I've added the rest of the fields as required (similar to keycloak).

I see there is this PR out for reorganizing the clustered docs, so maybe it can be done there to avoid conflicts? Let me know the best way forward, thanks!

• Signed the InfluxData CLA
  (if necessary)
• Rebased/mergeable

[sanderson]

Thanks @david-rusnak! I'll take care of porting these over to the other PR.

[david-rusnak]

@sanderson Hey Scott, just a note on this that @eatondustin1 brought up to me. While it's true that the email can be arbitrary for auth purposes, for any auditing the customer wants to do - they should probably use a valid email/identifier so any actions that track the user who initiated it can be audited later.