Bumhug: GameFixes and GameFeatures classes should be split into separate plugins for every fix/feature

The current pattern is a remnant of SimpleAdminHacks. Splitting them into separate plugins means that we can use them piecemeal as needed, and encourages us to remove unused hacks instead of letting them linger in Bumhug.

• AutoSilkTouch
• Cardinal
• ChunkLimits
• CombatDamageTweak
• CTAnnounce
• DeathMessages
• FreeAnvil
• DisableVillagerTrading (GameFeatures)
• DisableWitherSpawning (GameFeatures)
• DisableEnderChests (GameFeatures) (should be moved into EnderBender)
• DisableEnchantingTable (GameFeatures)
• DisableNaturalXp (GameFeatures)
• DisableNetherPortal (GameFeatures)
• DisableIronGolemVillagerSpawning (GameFeatures)
• PreventStorageTeleport (GameFixes)
• PreventBedBombing (GameFixes)
• PreventFallingThroughBedrock (GameFixes)
• Gamma
• GhostBlockBlock
• IntervalAnnouncement
• InvSee
• MinecartTeleporters
• NBTShow
• NewfriendAssist
• ObsidianGenerators
• Pathing
• PearlCooldown
• PingCommand
• RaiderAnnounce
• SaveDeathInventory
• SetBedSpawn
• SetRepairCost
• SpaceGuard
• TeruTeruBozu