Vision granularity audit: Military (or just FEMA Camps)

[sonphantrung]

Summary

Content "Add more vision level (at least for FEMA camps, for now)"

Purpose of change

I find it strange how a building with multiple tents is treated the same as a concrete building.

Describe the solution

Added a new overmap terrain vision called isolated_camp (sure, there are body sites there, but mostly the thing that stands out most are tents)

Describe alternatives you've considered

Leave it as is

Testing

Tested w/ a FEMA refugee camp:

Additional context

I'll do more later on, this is just the beginning