#40237 regression: validate the subscription status on unban

Proposed changes (including videos or screenshots)

Issue(s)

Introduced by #40114
FGA-65

Steps to test or reproduce

Further comments

Summary by CodeRabbit

• Bug Fixes
  • Improved error handling during user unban operations in rooms. The system now correctly distinguishes between invite subscriptions and other non-banned subscription states, and returns an appropriate error message when attempting to unban users who were not actually banned from the room, ensuring more reliable operations.