Add moc as a parameter to HealpixDataset and subclasses

[smcguire-cmu]

Adds the moc optional parameter to the HealpixDataset class. This enables keeping track of and using the coverage of a catalog at a higher order than the partition pixels, which will allow us to do more efficient alignments for joins and crossmatches in LSDB.

Adds loading the MOC from the point_map.fits file if it exists when a catalog is loaded.

Code Quality

• [x] I have read the Contribution Guide
• [x] My code follows the code style of this project
• [x] My code builds (or compiles) cleanly without any errors or warnings
• [x] My code contains relevant comments and necessary documentation

Project-Specific Pull Request Checklists

New Feature Checklist

• [x] I have added or updated the docstrings associated with my feature using the NumPy docstring format
• [ ] I have updated the tutorial to highlight my new feature (if appropriate)
• [x] I have added unit/End-to-End (E2E) test cases to cover my new feature
• [ ] My change includes a breaking change
  • [ ] My change includes backwards compatibility and deprecation warnings (if possible)

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 94.22%. Comparing base (7e27775) to head (40a8594). Report is 2 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #263 +/- ## ========================================== + Coverage 94.15% 94.22% +0.07% ========================================== Files 56 56 Lines 1915 1940 +25 ========================================== + Hits 1803 1828 +25 Misses 112 112 ```

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Before [5bcb4703]	After [596122de]	Ratio	Benchmark (Parameter)
13.4±0.09ms	13.8±0.1ms	1.04	benchmarks.time_test_cone_filter_multiple_order
19.2±0.6ms	19.7±0.6ms	1.03	benchmarks.MetadataSuite.time_load_partition_info_order6
75.6±0.3ms	77.3±0.5ms	1.02	benchmarks.MetadataSuite.time_load_partition_info_order7
75.7±0.8ms	77.2±0.6ms	1.02	benchmarks.MetadataSuite.time_load_partition_join_info
38.9±1ms	39.5±1ms	1.02	benchmarks.Suite.time_pixel_tree_creation
13.0±0.2ms	13.1±0.3ms	1.01	benchmarks.Suite.time_inner_pixel_alignment
85.8±2ms	86.4±2ms	1.01	benchmarks.Suite.time_paths_creation
125±0.5ms	124±0.4ms	0.99	benchmarks.time_test_alignment_even_sky
373±3ms	363±3ms	0.97	benchmarks.Suite.time_outer_pixel_alignment

Click here to view all benchmarks.