Allow explicit config to select permission system

[meza]

Feature Description:

Currently dynmap guesses which permission system is available based on an arbitrary presedence. Luckperms > Fabric Permissions Api > permissions.yml

The issue is that some mods might add the permissions api for their own benefit. This can happen completely outside of the control of the server owner. (I just had this issue with Spark).

I would like to be able to tell dynmap that regardless that the fabric permissions api exists on the classpath, please use the permissions.yml instead.