Lightweight GroupChat Plugin for 1.7.10-1.18.2

- /groupchat create `<name>` - Creates a new group with the specified name.
- /groupchat delete - Deletes the current group.
- /groupchat invite `<player>` - Invites the specified player to the current group.
- /groupchat join `<group name>` - Joins the specified group.
- /groupchat leave - Leaves the current group.
- /groupchat list - Lists all available groups.
- /groupchat mygroups - Lists all groups the player is a member of.
- /groupchat info `<group name>` - Provides information about the specified group.
- /groupchat say `<message>` - Sends a message to the current group.
- /groupchat toggle - Toggles group chat mode on or off.