Many minor changes to address all of @Anxuiz's comments

Remove all default constructors project-wide

Pass PlayerManager instead of ChatModeratorPlugin in all Filters

Remove extra null-check in PlayerViolationManager

Make default violation levels configurable and soft-coded

Cache Instant.now() in DuplicateMessageFilter so it doens't change.

Clean up imports on all Filters

Log to the console on un/registering filters

Reworked logging project-wide

Minor cleanup

Remove extra default constructors

Clean up the `Iterator` when un-registering filters.