Fix duplicate extension's help command permission registration on Paper

[onebeastchris]

Fixes #4078 by checking if a permission already exists before attempting to add it.

Caused by Geyser registering multiple /<extensionid> help commands under the same permission.
This fix would just avoid re-registering these permissions.
To help debugging issues, the duplicated permissions are logged in debug mode.

Additionally, i removed the check for floodgate-bukkit, which was added two years ago.

[Konicai]

Shouldn't the extensions's ID be a part of its help command permission? I don't understand why the permission was chosen to be the same or every extension help instance.

[onebeastchris]

It could be, but what's the point restricting some extensions help command? Either you want to see all command listings for all extensions, or for none :p
Personally, i would leave the permission as is, and just avoid re-registering it

[Konicai]

Same reason as not having every single /spigotPlugin help command be under the same permission

extensions that aren't targeted towards the base player don't need to be exposed in that regard

[onebeastchris]

OK, valid. I'll change the permissions to include the extension id - i personally would leave in the duplicate permission check though in case two extensions try to register a command with the same permission.

[onebeastchris]

with the latest changes, all extension's help/? commands have separate permissions.

[onebeastchris]

Also noticed the wrong header for extension help commands; fixed that too


Now it shows "Geyser extensions" instead of "Showing Help For: Geyser" when running an extensions help command.

Ideally, it would show "Showing help for %extensionname%", not sure if that can be easily done