Toggle per type and various fixes

New features:

• The toggle command now supports an optional parameter so that players can toggle notifications per achievement type, e.g. /aach toggle rare. This is intended as a hidden feature, the achievement types are not surfaced in the in-game completion proposals.

Bug fixes:

• Suppressed some remaining warnings that were displayed at startup when using a gui.yml file generated before Advanced Achievements 6.7.0 on Minecraft 1.12 or older servers.
• Reduced risk of conflicts with database drivers provided by other plugins. This happened recently with one of the LuckPerm releases.

API:

• Added missing getType method to PlayerAdvancedAchievementEvent.