Refactor and add tests to merge_tops_bursts.py

[forrestfwilliams]

Add tests for most functions inside of merge_tops_bursts.py. Also includes many refactors that were exposed as needed when testing was implemented.

Notably tests have not been added for the following functions:

• merge_tops_bursts
• package_output
• run_isce2_workflow
• prepare_products
• mask_coherence
  The rational here is that these are all "workflow style" functions that mainly group calls to several well-tested functions.

[github-actions]

Coverage Report

File	Stmts	Miss	Cover	Missing
/home/runner/micromamba/envs/hyp3-isce2/lib/python3.11/site-packages/hyp3_isce2
__main__.py	26	2	92%	33, 44
burst.py	250	55	78%	98–101, 114–119, 133–148, 164–173, 187–197, 255, 303–311, 331–345, 583–585, 611
dem.py	53	3	94%	101–110
insar_stripmap.py	69	42	39%	38–91, 95–97, 114–133
insar_tops.py	57	30	47%	49–87, 110–132
insar_tops_burst.py	227	179	21%	83–155, 167–193, 223–306, 360–362, 375–468, 492–508, 544–628
logging.py	4	1	75%	9
merge_tops_bursts.py	605	88	85%	182, 199, 261, 266, 323, 339, 347, 379, 383, 468, 495, 572, 612–630, 679–683, 707, 712, 771, 794, 923, 1060–1080, 1095–1108, 1122–1143, 1154–1159, 1166–1179, 1183
s1_auxcal.py	21	2	90%	51, 59
slc.py	34	10	71%	22–25, 29–34
stripmapapp_alos.py	50	7	86%	102, 138, 141–146
topsapp.py	70	8	89%	77, 107, 129–135
utils.py	199	6	97%	113–124, 129, 235, 396, 441
water_mask.py	59	5	92%	88, 100–103
/home/runner/micromamba/envs/hyp3-isce2/lib/python3.11/site-packages/hyp3_isce2/metadata
util.py	14	9	36%	6–14, 18–21, 25–27
TOTAL	1750	447	74%

Tests	Skipped	Failures	Errors	Time
84	1 💤	0 ❌	0 🔥	30.871s ⏱️