Check opencsp.common for doc strings

[e10harvey]

Purpose

Ensure that public entities in opencsp/common have doc strings. Related to #36.

Summary of changes

• Updated test_docstrings_exist to check opencsp/common
• Added missing doc strings

Implementation notes

Ran pytest -k test_docstrings

Submission checklist

• Target branch is develop, not main
• Existing tests are updated or new tests were added
• opencsp/test/test_DocStringsExist.py are verified to include this change or have been updated accordingly
• .rst file(s) under doc/ are verified to include this change or have been updated accordingly
  • Given the size of these changes, I'll address this in the follow-on issue [Code Feature]: Update doc/source to include all of opencsp/common #182

Additional information

TODOs:

• camera
• csp
• csp/ufacet
• cv
• cv/annotations
• cv/fiducials
• cv/spot_analysis (Skipped in favor of 177 RST stubs for ReadTheDocs #178)
• deflectometry
• file
• geo
• geometry
• opencsp_path
• photogrammetry
• process
• process/lib
• render
• render/lib
• render_control
• target
• tool
• uas

[e10harvey]

Reviewers, I'd be happy to break this into separate PRs, one for each of:

• camera
• csp
• csp/ufacet
• cv
• cv/annotations
• cv/fiducials
• cv/spot_analysis (Skipped in favor of 177 RST stubs for ReadTheDocs #178)
• deflectometry
• file
• geo
• geometry
• opencsp_path
• photogrammetry
• process
• process/lib
• render
• render/lib
• render_control
• target
• tool
• uas

[e10harvey]

Closing in favor of separate, smaller PRs.