feat(port, content): freshwater research station

[Vollch]

Purpose of change

Freshwater Research Station is a neat special to have.
It's mostly JSON thing, but also includes tiny yet vital C++ change, required for all other underwater specials(aircraft carrier).

Describe the solution

Ported PRs:

• add freshwater research station and associated terrain/furniture. CleverRaven/Cataclysm-DDA#42107
• balance for freshwater research station CleverRaven/Cataclysm-DDA#43249
• Adjust shark suit spawn type CleverRaven/Cataclysm-DDA#43304
• fix freshwater research station spawning CleverRaven/Cataclysm-DDA#45552
• adjust loot spawns in freshwater research station CleverRaven/Cataclysm-DDA#45766
• Freshwater research station roof map added CleverRaven/Cataclysm-DDA#51323
• Fix missing floors in freshwater research station roof CleverRaven/Cataclysm-DDA#53843

With minimal changes:

• Move cost of t_door_metal_bulkhead_o increased from 1 to 2. Such doors are not allowed in BN. (Add check for suspicious move_cost in terrain #2252)
• Removed city constraints from specials. It had "city_sizes": [ 1, 20 ] which does pretty much nothing, except confusing mapgen.

Describe alternatives you've considered

Also porting vertical swimming, and two way ladders. Both are good, but not directly related - they will be ported separately.

Testing

Spawned via debug; found naturally generated one; started in it from Safe Place scenario. All works.

Additional context

Checklist

[chaosvolt]

heccin' case-sensitive semantic PR thing

[scarf005]

heccin' case-sensitive semantic PR thing

average CapitalCase fan vs average lowercase enjoyer

EDIT: port is not a valid type, changed to feat.

[chaosvolt]

Whoops, nice. That explains why it was failing, and glad it successfully checked itself off once corrected.

[scarf005]

hopefully semantic PR bot will be a more helpful after #3672.

[scarf005]

A very nice addition.

I also approv of the usage of Co-authored-by here.