Moving around library code into ingress/analysis/visualizetion submodules

[sbenthall]

Except where covered by other PRs. Fixes #537

[codecov-commenter]

Codecov Report

Merging #540 (4c4b6ba) into main (035bc60) will decrease coverage by 0.09%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #540      +/-   ##
==========================================
- Coverage   74.83%   74.74%   -0.10%     
==========================================
  Files          22       22              
  Lines        3052     3041      -11     
==========================================
- Hits         2284     2273      -11     
  Misses        768      768              

Flag	Coverage Δ
unittests	74.74% <100.00%> (-0.10%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
bigbang/analysis/entity_resolution.py	83.05% <ø> (ø)
bigbang/analysis/process.py	44.69% <ø> (ø)
bigbang/analysis/thread.py	68.67% <ø> (ø)
tests/unit/test_archive.py	95.12% <ø> (-0.63%)	⬇️
bigbang/analysis/repo_loader.py	47.43% <100.00%> (ø)
bigbang/archive.py	71.01% <100.00%> (ø)
bigbang/ingress/git_repo.py	69.36% <100.00%> (ø)
bigbang/ingress/mailman.py	61.42% <100.00%> (ø)
bigbang/w3crawl.py	91.20% <100.00%> (ø)
tests/unit/test_bigbang.py	97.88% <100.00%> (ø)
... and 1 more

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[sbenthall]

Tests are passing and there's no pushback so I'll merge by the end of the day.