Deny Muted users permissions to send messages in threads

[Victoria-DR]

Purpose

Currently, those with the Muted role only have the ADD_REACTIONS, SEND_MESSAGES, and SEND_TTS_MESSAGES denied. With the introduction of threads, we also need to prevent them from creating threads, sending messages in them, and using slash commands.

Proposed Solution

Deny the additional relevant permissions (full list here) in the applyMute handler.

Acceptance Criteria

Please list the requirements the implementation of this feature should meet.

• [ ] Users with the Muted role should not be able to create private or public threads, nor send messages in existing threads.
• [ ] They also should not be able to use slash commands.

[Victoria-DR]

Will work on this after the mute commands are ported over to v13.