Add mongodb_to_bigquery yaml blueprint example and e2e test

[derrickaw]

1. Part of Phase 6? :) - [Task]: YAML - E2E example pipelines for common use cases #35030

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 56.23%. Comparing base (76f6e6d) to head (e370a2a).
⚠️ Report is 108 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff              @@
##             master   #40485      +/-   ##
============================================
+ Coverage     56.16%   56.23%   +0.06%     
  Complexity     2288     2288              
============================================
  Files          1124     1124              
  Lines        178336   178362      +26     
  Branches       1489     1489              
============================================
+ Hits         100170   100307     +137     
+ Misses        75645    75534     -111     
  Partials       2521     2521              

Flag	Coverage Δ
python	79.69% <ø> (+0.14%)	⬆️

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[github-actions]

Assigning reviewers:

R: @shunping for label python.
R: @chamikaramj for label yaml.

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