[Task] Change `RedactionSynchronisationProtection` to check on ban events rather than on ban policies.

[Gnuxie]

This is a simplification of https://github.com/the-draupnir-project/planning/issues/10, and allows us to develop something now without waiting for the timeline cache.

Acceptance Criteria

• Any ban of a user from a room by either the bot or a moderator invokes the check against config.automaticallyRedactForReasons to redact the messages.

Issues

• https://github.com/the-draupnir-project/Draupnir/issues/76
• https://github.com/the-draupnir-project/Draupnir/issues/156
• https://github.com/the-draupnir-project/Draupnir/issues/382

Dependencies

None

Total Pain

40