Return HTTP response as second return value from typed API client functions

[ste93cry]

Description

I'm refactoring the functions of the typed clients to return the HTTP response as second value.

Issues Resolved

Closes #619

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[codecov]

Codecov Report

Attention: Patch coverage is 99.37107% with 7 lines in your changes missing coverage. Please review.

Project coverage is 56.70%. Comparing base (06a6dc8) to head (574ee61).
Report is 70 commits behind head on main.

Files with missing lines	Patch %	Lines
opensearchapi/api_cat.go	95.00%	6 Missing ⚠️
opensearchapi/api_cluster.go	98.61%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #624      +/-   ##
==========================================
- Coverage   57.29%   56.70%   -0.59%     
==========================================
  Files         315      374      +59     
  Lines        9823     8036    -1787     
==========================================
- Hits         5628     4557    -1071     
+ Misses       2902     2171     -731     
- Partials     1293     1308      +15     

Flag	Coverage Δ
integration	56.70% <99.37%> (+5.86%)	⬆️
unit	?

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
opensearchapi/api_aliases.go	100.00% <100.00%> (ø)
opensearchapi/api_bulk.go	100.00% <100.00%> (ø)
opensearchapi/api_cat-aliases.go	100.00% <ø> (ø)
opensearchapi/api_cat-allocation.go	100.00% <ø> (ø)
opensearchapi/api_cat-cluster_manager.go	100.00% <ø> (ø)
opensearchapi/api_cat-count.go	100.00% <ø> (ø)
opensearchapi/api_cat-fielddata.go	100.00% <ø> (ø)
opensearchapi/api_cat-health.go	100.00% <ø> (ø)
opensearchapi/api_cat-indices.go	100.00% <ø> (ø)
opensearchapi/api_cat-master.go	100.00% <ø> (ø)
... and 197 more

... and 156 files with indirect coverage changes

[dblock]

Big breaking change :(

If data, response, err was flipped as data, err, response, would it be easier to migrate to? Does go allow to specify the first 2 objects and omit the third?

[ste93cry]

No, it doesn’t. Also, it's conventional in Go to return error as last value. But, even though it’s a breaking change, it’s quite easy to track it and solve it as the project will not compile until the new returned value is either ignored or handled, and find and replace in most cases might be all a user needs to do if he never bothers about the response. Considering that this change is targeting the next major version, where this kind of things is expected to happen, I don’t see big downsides.