Add row_query callback to apmgorm

[Vilsol]

The RowQuery callback is used when objects are queried with functions like row, rows, count, etc are executed.

[codecov-io]

Codecov Report

Merging #532 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #532      +/-   ##
==========================================
+ Coverage   84.13%   84.13%   +<.01%     
==========================================
  Files         115      115              
  Lines        6757     6758       +1     
==========================================
+ Hits         5685     5686       +1     
  Misses        767      767              
  Partials      305      305

Impacted Files	Coverage Δ
module/apmgorm/context.go	88.57% <100%> (+0.16%)	⬆️

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[axw]

@Vilsol thanks for the PR!

Would you please add a test?

Also, in case you haven't already noticed, there is a CLA which requires signing. Let me know if you're having trouble with that.

[Vilsol]

@axw Thanks, I assumed that commits signed by Github's key also count as signed? If not, how can I re-sign the commit with my own key?

[axw]

@Vilsol the message "Pull request contains unsigned commits" is perhaps a bit unclear. Your commits are signed and that's fine, but it appears that you have not signed the CLA.

Did you already sign the CLA at https://www.elastic.co/contributor-agreement? Maybe with another email?

[axw]

(Ah, I just got what you meant. I'll have to check about using GitHub's key.)

[Vilsol]

Ah, I got it now, the signed commits are related to the contributor agreement not GPG signing. Might want to make the error message more descriptive.

[axw]

Thank you for the fix. Can you please add a test that demonstrates why this is needed?
Or perhaps just modify testWithContext in apmgorm_test.go to make an additional query that requires it?

[axw]

I've picked up the task of adding a test. I'll close this and continue over in #543. Thanks for the fix @Vilsol!