Raid Control Improvements

[woojiahao]

There are lots that can be done to enhance the raid control of the bot:

1. Check/log the type of message and frequency of the same message before muting the raider (This should be toggled on/off since in a big raid, there's no time to do these minute checks)
2. Checking the length of a message will also help as short spammy messages should be caught whereas a long message just because the user can type fast should not be caught
3. Track user join rates for each server. If the join rate within X seconds increases suddenly, then the bot should be able to increase the security of the server automatically (This should be toggled on/off)
4. Command to stricten the raid requirements when needed