Add rag enrichment and ingestion.

[claudevdm]

Add ingestion and enrichment components for rag pipelines.

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[claudevdm]

R: @damccorm

[github-actions]

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[damccorm]

This is awesome! Comments are all minor, I'm really excited with how this turned out!

[codecov]

Codecov Report

Attention: Patch coverage is 81.48148% with 25 lines in your changes missing coverage. Please review.

Project coverage is 59.05%. Comparing base (18ec331) to head (6f07040).

Files with missing lines	Patch %	Lines
...ks/python/apache_beam/ml/rag/ingestion/bigquery.py	64.86%	13 Missing ⚠️
...e_beam/ml/rag/enrichment/bigquery_vector_search.py	86.07%	11 Missing ⚠️
sdks/python/apache_beam/ml/rag/ingestion/base.py	94.11%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##             master   #33413      +/-   ##
============================================
+ Coverage     59.02%   59.05%   +0.02%     
  Complexity     3185     3185              
============================================
  Files          1146     1149       +3     
  Lines        176085   176219     +134     
  Branches       3368     3368              
============================================
+ Hits         103942   104073     +131     
- Misses        68787    68790       +3     
  Partials       3356     3356              

Flag	Coverage Δ
python	81.26% <81.48%> (+0.03%)	⬆️

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