feat: Add support for custom names and methods that return structs with multiple []*T fields in gen-iterators.go

[Not-Dhananjay-Mishra]

With customNames map we can assign custom names specifically for the iterator while keeping the original method name unchanged also with this we can give more understandable names for the iterator.

and some method like GetCommit and CompareCommits contains multiple []*T fields with sliceToBeUsedForIteration map we can specify which field should be used for iteration

Related : #4117

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.74%. Comparing base (f293a76) to head (1c55146).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #4128      +/-   ##
==========================================
+ Coverage   93.72%   93.74%   +0.01%     
==========================================
  Files         211      211              
  Lines       19621    19681      +60     
==========================================
+ Hits        18389    18449      +60     
  Misses       1034     1034              
  Partials      198      198              

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[gmlewis]

Thank you, @Not-Dhananjay-Mishra!
Just a few tweaks, please (you'll have to make these locally since the indentation and bracketing will change), then we should be ready for a second LGTM+Approval from any other contributor to this repo before merging.

cc: @stevehipwell - @alexandear - @zyfy29 - @munlicode

[Not-Dhananjay-Mishra]

@gmlewis Thanks again!
I've made all the changes.

[stevehipwell]

LGTM

[gmlewis]

Thank you, @Not-Dhananjay-Mishra and @stevehipwell!
LGTM.
Merging.