* Refactor /velocity command to use Brigadier * Added default usage message and code cleanup * Reimplemented callback subcommand * Fixed execution of the callback subcommand when all permissions of the main command subcommands are denied * Migrated callback subcommand to its own command * Migrated server command * GList, Send and Server command cleanup --------- Co-authored-by: Adrian <adriangonzalesval@gmail.com>