Client chat: Removing messages

[Qaomen]

Description To help moderate the client chat, any messages that are removed on the discord channel should subsequently be removed in the client chat.

Minimum Acceptance Criteria

• [ ] Server should provide the client chat with message IDs.
• [ ] Server should handle removed message events and notify the client chat.
• [ ] Client chat should delete discord-removed messages.

Is blocked by the following issues Related to #291 for message removal.