Ban appeals, create new category if full

[ChrisLovering]

The ban appeals plugin should support multiple categories in case more than 50 appeals are active at a time.

Optionally we can create a categories on failure and store the IDs in the DB, rather than hardcoding anything.

[ChrisLovering]

My idea for this is to remove the hardcoded category entirely and move everything into db config.

When a appeal thread is opened, if no category can be found, or all stored categories are full, then it creates a new one.

As for cleanup, we can have a delete category command, which deletes in discord, and in the db. Along with a sync command (maybe on init too?) that checks to see if the categories in the db still exist.