Support HyP3's INSAR_ISCE_MULTI_BURST job type (#1430)

* parse new file naming convention for burst-based insar products from HyP3

* add test cases for prep_hyp3.add_hyp3_metadata

* rough draft of supporting three hyp3 job types for insar

* fix _get_product_name_and_type for current tests

* fix filenames in test_prep_hyp3

* add todo

* todos

* simplify add_hyp3_metadata

* cleanup comments

* fix docstring quotes

* add todo

* update prep_hyp3 for multi-burst dash to underscore

* make single-burst test pass for prep_hyp3

* insar gamma regex

* single-burst insar regex

* finish regex matching for insar product names

* test_get_product_name_and_type

* add error cases to test_get_product_name_and_type

* remove some todos

* update add_hyp3_metadata docstring

* reformat/rename test_prep_hyp3 unit tests

* add test_data_dir fixture

* simplify test_data_dir fixture

* add pytest to circleci

* add pytest to dependencies

* scope pytest to entire tests/ dir

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Co-authored-by: Andrew Johnston <asjohnston@alaska.edu>