Random Mob Sizes

• fix mobs not dropping any loot when scale_loot is turned off
• change how/when default values are used
• fix config option scale_xp not affecting the dropped xp
• create additional option for scaling health, attack damage or movement speed

Full Changelog: https://github.com/tristankechlo/RandomMobSizes/compare/1.21-2.2.0...1.21-2.2.1