Stop using BDs global variables

[aarondoet]

BetterDiscord currently still has global variables like bdplugins but they will get removed soon.
You are using the following globals:

• bdplugins (1, 2, 3)

Also you should not be using global variables, just use let to create them. Then they won't be global and your plugin can still access them all.

Please also don't delete globals used by others, this will cause a problem when your plugin loads the library first but another one is also using it. (Just don't use the remote library at all. Tell the user that the library is missing and don't use the remote library instead.)