Rework Warn System

[FrozenChen]

• Now there is 2 types of warns, ephemeral and pinned
  • ephemeral warns are the default type of warn and expire after 180 days
  • pinned warns are applied with the .pinwarn command (works the same as .warn), pinned warns do not expire and are only deleted by staff.
  • Expired or deleted warns are still kept in the DB and can be seen with the modsense slash command.
• All old warns will be converted to ephemeral warns meaning a lot of warns will be deleted once its implemented.
  • It's straight up impossible to check warns one by one to see which one should be a pinned warn, currently the DB has 6143 warns logged
• Added new slash command, multiwarn which can apply multiple warns at once, works the same as softwarn but you can also select if you want all the warns to be ephemeral or pinned (meaning you dont need to spam softwarn or pinwarn)