[Feat] no-render-return-undefined: disallow components rendering undefined

[akulsr0]

Closes #3020

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 44.32%. Comparing base (4467db5) to head (34b6a94).
Report is 3 commits behind head on master.

❗ Current head 34b6a94 differs from pull request most recent head 8aec646. Consider uploading reports for the commit 8aec646 to get more accurate results

Additional details and impacted files

@@             Coverage Diff             @@
##           master    #3750       +/-   ##
===========================================
- Coverage   97.71%   44.32%   -53.40%     
===========================================
  Files         133        6      -127     
  Lines        9470      282     -9188     
  Branches     3469      102     -3367     
===========================================
- Hits         9254      125     -9129     
+ Misses        216      157       -59     

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[akulsr0]

@ljharb Let me know your thoughts on this!