add get_modules convenience

[bjlittle]

🚀 Pull Request

Description

This pull-request adds a geovista.common utility to recursively discover the (dot notation) modules belonging to a (dot notation) package.

Initial application targets example script discovery in geovista.cli, and support for image testing of example scripts.

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[codecov]

Codecov Report

Attention: 1 lines in your changes are missing coverage. Please review.

Comparison is base (d449616) 94.85% compared to head (2d81f7f) 94.86%.

Files	Patch %	Lines
src/geovista/common.py	92.30%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #541   +/-   ##
=======================================
  Coverage   94.85%   94.86%           
=======================================
  Files         116      117    +1     
  Lines        4701     4728   +27     
=======================================
+ Hits         4459     4485   +26     
- Misses        242      243    +1     

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