refactor: move aimbat source to src directory

[smlloyd]

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📚 Documentation preview 📚: https://aimbat--212.org.readthedocs.build/en/212/

[codecov]

Codecov Report

❌ Patch coverage is 38.46154% with 16 lines in your changes missing coverage. Please review.
✅ Project coverage is 93.06%. Comparing base (99faf2f) to head (185c8f4).
⚠️ Report is 2 commits behind head on master.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
src/aimbat/cli/iccs.py	46.66%	8 Missing ⚠️
src/aimbat/lib/iccs.py	0.00%	8 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #212   +/-   ##
=======================================
  Coverage   93.06%   93.06%           
=======================================
  Files          32       32           
  Lines        1615     1615           
=======================================
  Hits         1503     1503           
  Misses        112      112           

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