Fix outside_footprint for spherical coordinates

[nden]

Follow up on #498
When spherical coordinates and the footprint are around (0, 0) shift them all to be less than 180 before comparing the range.

[codecov]

Codecov Report

Attention: Patch coverage is 81.81818% with 2 lines in your changes missing coverage. Please review.

Project coverage is 87.48%. Comparing base (9cd8552) to head (35860b8).
Report is 9 commits behind head on master.

Files with missing lines	Patch %	Lines
gwcs/wcs.py	81.81%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #535      +/-   ##
==========================================
+ Coverage   87.42%   87.48%   +0.05%     
==========================================
  Files          22       22              
  Lines        3874     3938      +64     
==========================================
+ Hits         3387     3445      +58     
- Misses        487      493       +6     

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[mcara]

Coordinates already should be in the [0, 360] and [0, 180] (or [-90, 90]) range. Taking mod at 180 does not look like the correct approach. I think there may be cases when this could fail. For example, take CRVAL at 180 and an image that spans from ra=179.8 to 180.1.

Try adding some unit tests for this.

Also a good time to replace range with something else like world_range.