Cave jsonify

[Night-Pryanik]

Summary

SUMMARY: Content "Cave jsonify."

Purpose of change

Jsonify and make cave location more interesting.

Hardcoded cave location was boring and uninteresting as hell, both from atmosphere and gameplay point of view. There was almost no reason to delve into the caves.
Initially I just wanted to jsonify the mapgen and call it a day, but eventually decided to rework location to be more fun and interesting. I'm not saying that now caves are THAT interesting, but at least they are more interesting than previous squares of cave floor with almost no loot and design.

Describe the solution

• Added several above-ground and underground variants and made them spawn in the world. Above-ground variants all have the same chance to spawn. They aren't differ that much - there are "bats", "spiders", "cougars", "bear" and some other variants with similar layout.
  Underground variants differ heavily, with the "trash and monster parts" variant being the most common. There are also "archeology site", "cave minerals and broken molebots", "survivor's hideout", "giant naked molerats" and some other variants with lower chance to spawn.
• Caves now spawn only in forests rather than almost everywhere, and at least 5 distance from cities. This change makes them spawn rather rarer than before.
• Removed hardcoded mapgen.

Describe alternatives you've considered

None.

Testing

Teleported around the map, found several caves, searched through them.

Additional context

Some of above-ground variants:

Some of underground variants: