feat: Implement Spigot Compatibility

[4drian3d]

Some functions of the paper module have been modified, for example:

• Use getLogger instead of getSLF4JLogger.
• User PluginManager#callEvent instead of Event#callEvent

To be able to support Spigot 1.8-1.11+

This pull request has not been tested in these environments, so there won't be full support when using them there, but it should work

Also:

• fix: Fixed possible NullPointerException in case the configuration could not be loaded