Add paths method for getting multiple paths

[smcguire-cmu]

Looping through pixel_catalog_file can be inefficient, so add pixel_catalog_files method which generates multiple paths.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 95.74%. Comparing base (10e527d) to head (238c074).
Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #258      +/-   ##
==========================================
+ Coverage   95.72%   95.74%   +0.01%     
==========================================
  Files          56       56              
  Lines        1873     1880       +7     
==========================================
+ Hits         1793     1800       +7     
  Misses         80       80              

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[github-actions]

Before [af5806a]	After [7e64f04]	Ratio	Benchmark (Parameter)
failed	20.3±0.5ms	n/a	benchmarks.MetadataSuite.time_load_partition_info_order6
failed	77.2±0.5ms	n/a	benchmarks.MetadataSuite.time_load_partition_info_order7
failed	77.2±0.3ms	n/a	benchmarks.MetadataSuite.time_load_partition_join_info
failed	86.6±3ms	n/a	benchmarks.Suite.time_paths_creation
failed	46.9±0.6ms	n/a	benchmarks.Suite.time_pixel_tree_creation
failed	124±0.2ms	n/a	benchmarks.time_test_alignment_even_sky
failed	13.7±0.1ms	n/a	benchmarks.time_test_cone_filter_multiple_order

Click here to view all benchmarks.

[camposandro]

Looks good!

It'd be great to check how much it improved - can you add a benchmark test to this?