[NO MERGE] Contextual Data API

[aromaa]

Sponge | SpongeAPI

Implemented data directions:

• [x] Entity -> Entity
• [x] Entity -> Team
• [ ] Entity -> World
• [x] Team -> Entity
• [x] Team -> Team
• [ ] Team -> World
• [ ] World -> Entity
• [ ] World -> Team
• [ ] World -> World

Implemented data operations:

• [x] offer
• [ ] offerSingle
• [ ] offerAll
• [ ] removeSingle
• [ ] removeAll
• [x] remove