server: Add all missing dummy handlers.

- Handle 0x07: EntityInteract
- Handle 0x0E: PlayerAction
- Handle 0x0F: PlayerBlockPlace
- Handle 0x66: WindowClick
- Handle 0x6A: ConfirmTransaction
- Handle 0x6C: EnchantItem
- Handle 0x82: SignUpdate
- Handle 0xFA: PluginMessage