Implement moderation features

[HeadTriXz]

Create a set of moderation tools to help moderators manage user behavior and enforce server rules. This includes features such as banning, kicking, muting, and warning.

Moderators should be able to view the history of cases, and delete specific cases if needed. Adding, editing, deleting, and viewing notes on a case should also be possible.

To-do

• Create command for banning users #14
• Create command for kicking users #15
• Create command for muting users #16
• Create command for warning users #17
• Create command for adding notes to users #18
• Create command for unbanning users #19
• Create command for unmuting users #20
• Create command for purging messages #21
• Create command for marking users as "deal with caution" #22
• Create command for managing cases #23