Add ProtectionTypes that respect where the event came from
- Added ProtectionType.FLOW_IN, which will only prevent liquids from flowing into protected regions, not from flowing within or flowing out of protected regions
- Added ProtectionType.PISTONS_IN, which will only prevent pistons from pushing or pulling blocks from outside of a protected region, not operating within one or pushing/pulling blocks outside
- ProtectionType.PISTONS is no longer included in ProtectionType.INDIRECT_PLAYERS, but PISTONS_IN is