Spawn levels upon entering suitable biome #2

[meetcshah19]

Contains the changes to spawn levels/challenges at the biome centre.

The levels spawn upon entering a suitable biome. The well is supposed to spawn near a water body ( in Coast, Beach and Lakeshore biomes). All other levels are supposed to spawn once the well is spawned (one each in Desert, Plains and Forest).

Testing instructions : (use hspeed and ghost in the console for faster testing)

• Try to go near a water body to spawn the well
• Once the well is spawned try finding desert, plains and forest biomes

Depends on https://github.com/Terasology/Lost/pull/10

Note: Test with https://github.com/Terasology/PolyWorld/pull/22

[jdrueckert]

Generally the spawn check approach seems unnecessarily imperformant. For instance I don't think we need the neighbour checks. If we find a suitable size for spawnArea then we can simply check the region biomes and see if all that we need are present in this area. They don't need to be adjacent.

[Cervator]

Not sure why the commit doesn't show at the bottom here (merge commit with conflict resolution) but I updated the branch so it'll build in Jenkins again (minor conflict over a changed import for NUI)

[Cervator]

Did final testing after most recent discussion on Discord, can sign off on this still testing off and being merge-worthy, woohoo! Finally crossed the finish line :-)

Always more we can do, but glad to call this one done. Thanks again @meetcshah19 and @jdrueckert for all the review!