Sort attributes by name in HTMLElement plugin

[pedrottimark]

Summary

The HTMLElement plugin has sort method for attributes, but because array consists of objects, it does not have same effect of enforcing consistent order of props like ReactElement and ReactTestComponent plugins where array consists of keys.

Goal: expected test criterion depends on what are the attributes, not on how they were set.

@mute Can you comment whether this change makes sense for serialized HTML elements?

Test plan

• changed expected results of 2 tests in which id preceded class
• changed received value of one test so it is already in sorted order
• wrote 2 comments because it looks like Jest does not use invariant to prevent that kind of subtle regression in tests

[mute]

This seems like a good change to me,

I think it could result in broken tests compared to existing snapshots, so it might necessitate a bump in the snapshot version, although I'm not sure how that process works.

[codecov-io]

Codecov Report

Merging #3783 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #3783      +/-   ##
==========================================
+ Coverage   58.01%   58.02%   +<.01%     
==========================================
  Files         195      195              
  Lines        6741     6742       +1     
  Branches        6        6              
==========================================
+ Hits         3911     3912       +1     
  Misses       2827     2827              
  Partials        3        3

Impacted Files	Coverage Δ
packages/pretty-format/src/plugins/html_element.js	94.28% <100%> (+0.16%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 1199558...1897f6e. Read the comment docs.

[cpojer]

Please rebase

[pedrottimark]

Yes

[github-actions]

This pull request has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.
Please note this issue tracker is not a help forum. We recommend using StackOverflow or our discord channel for questions.