adds temporalBaselineDays search keyword

[SpicyGarlicAlbacoreRoll]

Adds temporalBaselineDays search keyword, provides exact matches
(See #198 )

[codecov-commenter]

Codecov Report

Merging #199 (7f0aede) into master (f0df348) will decrease coverage by 0.09%.
The diff coverage is 92.30%.

@@            Coverage Diff             @@
##           master     #199      +/-   ##
==========================================
- Coverage   89.58%   89.49%   -0.09%     
==========================================
  Files          51       51              
  Lines        1930     1933       +3     
==========================================
+ Hits         1729     1730       +1     
- Misses        201      203       +2     

Flag	Coverage Δ
unittests	89.49% <92.30%> (-0.09%)	⬇️

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Impacted Files	Coverage Δ
asf_search/ASFSearchOptions/validator_map.py	58.82% <ø> (ø)
asf_search/CMR/field_map.py	100.00% <ø> (ø)
asf_search/search/search.py	100.00% <ø> (ø)
asf_search/search/search_generator.py	95.90% <91.66%> (-1.58%)	⬇️
asf_search/CMR/subquery.py	100.00% <100.00%> (ø)
asf_search/download/download.py	65.00% <100.00%> (ø)