Reduce reads and file exists checks

[delucchi-cmu]

Change Description

Related to, but does not close, LSDB astronomy-commons/lsdb#1249

Solution Description

• Reduces the number of times we check if a file exists before reading it. We still want to occasionally check, in the case that there are legacy file names.
• Reduces the file_io API surface, as many methods are just a thin wrapper around Path methods.

Code Quality

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

[github-actions]

Before [b6cebe1]	After [3564a43]	Ratio	Benchmark (Parameter)
1.06±0.04ms	1.08±0.03ms	1.02	benchmarks.time_test_cone_filter_multiple_order
267±2ms	269±2ms	1.01	benchmarks.time_small_cone_large_catalog
118±0.4ms	119±1ms	1.01	benchmarks.time_test_alignment_even_sky
5.40±0.4ms	5.39±0.4ms	1	benchmarks.ConeFilterSuite.time_cone_filter_benchmark
268±2ms	269±3ms	1	benchmarks.time_open_large_catalog
44.0±0.3ms	43.8±0.3ms	1	benchmarks.time_open_midsize_catalog
13.2±0.3ms	13.0±0.5ms	0.99	benchmarks.Suite.time_inner_pixel_alignment
395±1ms	393±1ms	0.99	benchmarks.Suite.time_outer_pixel_alignment
42.0±0.8ms	41.6±0.5ms	0.99	benchmarks.Suite.time_pixel_tree_creation

Click here to view all benchmarks.

[codecov]

Codecov Report

❌ Patch coverage is 96.42857% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 92.56%. Comparing base (b6cebe1) to head (a42edc4).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
src/hats/io/parquet_metadata.py	80.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #639      +/-   ##
==========================================
- Coverage   92.70%   92.56%   -0.15%     
==========================================
  Files          51       51              
  Lines        2702     2675      -27     
==========================================
- Hits         2505     2476      -29     
- Misses        197      199       +2     

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[smcguire-cmu]

lgtm!