Sky Archipelago

- [Added] Village placement on islands, 3 categories (Solo, hamlet and full) allowing for smaller villages/outposts, hamlets and full fledged villages to spawn. 
- [Added] Village filter for spawning of villages making it support modded villages. (Based on `village` existing in full id)
- [Added] Jigsaw structures spawning partially underground based on `start_height`
- [Added] Water based structure spawning on ocean layer *(OCEAN ENABLED ONLY, pending 1.4 for added support to floating islands)*
- [Added] New category `STRONGHOLD` to allow configuration for modded strongholds to use the island placement approach.
- [Added] Island overlapping logic in Advanced Settings
    - `void` => Destroys island overlap downward, existing approach
    - `overlap` => Overlap over an island keeping all terrain in tact
    - `crater` => Creates a crater in the shape of the island overlapping 
- [Added] Exposed category tokens to Dedicated & Singleplayer JSON configurations
    - `water`, `sky`, `ground`, `underground`, `village`, `stronghold` categories available.
    - Enables configuration by keyword (e.g: adding `minecraft` to `ground` would result in any `minecraft*` to spawn on the ground. `minecraft:stronghold` would spawn on the ground instead, or tries to)

- [Changed] Sky based placement migrated to v2 
- [Changed] Underground based placement migrated to v2

- [Fixed] Savanna spawning with coarse dirt only, now spawning with grass. (Leftover from testing) 
- [Fixed?] Chunk failing to be saved. Guard rail in place to stop it from occuring, from limited testing could not replicate, but more testing is required.