Update particles (api12)

[MrHell228]

SpongeAPI | Sponge

ParticleOptions:

• Removed DIRECTION and POTION_EFFECT_TYPE options due to them being legacy
• Added OPACITY option to support ParticleTypes.ENTITY_EFFECT (it uses ARGB int as color, so it's represented as COLOR and OPACITY options)
• Added DESTINATION option to support ParticleTypes.VIBRATION
• Made ITEM_STACK_SNAPSHOT option to be explicitly not empty because minecraft throws exception on empty itemstack anyway
• Updated options description
  

PositionSource:

• Exposed minecraft interface (gabizou said it's fine to expose it)
• Can be reference to Entity with some vertical offset or reference to BlockPos (it's packed into vibration particle and sent to client)
• If made of entity, vibration particles will chase entity
• Probably not the best name because it sounds very similar with our Locatable but I can't come up with good name (maybe something like ResolvablePosition, idk)
• The only method it could have is Optional<Vector3d> position(World) (mirrored from original PositionSource) but I'm not sure if it should be exposed

[MrHell228]

Moved to api12 (maybe it could be done on previous PR but I don't know if it's possible)