feat: Support []string return type in gen-iterators.go

[gmlewis]

Fixes: #3979.
Relates to: #3978.

cc: @Not-Dhananjay-Mishra

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.52%. Comparing base (b02895e) to head (555f453).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #3980   +/-   ##
=======================================
  Coverage   93.52%   93.52%           
=======================================
  Files         207      207           
  Lines       17569    17569           
=======================================
  Hits        16432    16432           
  Misses        937      937           
  Partials      200      200           

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[gmlewis]

@Not-Dhananjay-Mishra - I'm going to call it a night... so I'll go ahead and merge this so as to not hold you up.
Feel free to add any comments you have even after I merge.
I tested this on your use case, and all tests passed, so hopefully you won't run into any problems.

[Not-Dhananjay-Mishra]

Thank you @gmlewis for merging this ❤️.
LGTM