LevelledMobs

Changelog:

• relocated kotlin internally for better compatibility with other plugins that also use kotlin
• removed kotlin reflection
• fix many issues with strategy distance-from-origin
• fix potential exception relating to custom drops
• fix error running /lm debug show-pdc-keys if there are no keys to show
• add LevelledMobsSpawnReason TRIAL_SPAWNER
• add to deathcause enum: CAMPFIRE
• misc code changes to hopefully prevent errors
• fix typo in debug message
• update CommandAPI to 9.6.0-snapshot