Input trigger setting removed

What changed

The chat input setting for enabling / or @ quick menu triggers was removed. Quick menu triggers are always enabled where the composer supports them.

Why this matters to the user

Users will no longer see this switch in message input settings. Existing saved values for this setting are ignored.

What the user should do

Nothing - automatic.

Notes for release manager

Merge this with other input/composer setting cleanup notes if release prep groups settings changes together.