feat(eslint-plugin): [member-ordering] add decorators support

[miluoshi]

Fixes #1863

This PR adds support for grouping decorated fields and methods separately, optionally specifying their accessibility. See updated docs for details.

I'm happy to answer any questions or discuss concerns.

[typescript-eslint]

Thanks for the PR, @miluoshi!

typescript-eslint is a 100% community driven project, and we are incredibly grateful that you are contributing to that community.

The core maintainers work on this in their personal time, so please understand that it may not be possible for them to review your work immediately.

Thanks again!

---

🙏 Please, if you or your company is finding typescript-eslint valuable, help us sustain the project by sponsoring it transparently on https://opencollective.com/typescript-eslint. As a thank you, your profile/company logo will be added to our main README which receives thousands of unique visitors per day.

[codecov]

Codecov Report

Merging #1870 into master will decrease coverage by 0.00%.
The diff coverage is 94.28%.

@@            Coverage Diff             @@
##           master    #1870      +/-   ##
==========================================
- Coverage   94.36%   94.36%   -0.01%     
==========================================
  Files         168      168              
  Lines        7651     7664      +13     
  Branches     2199     2204       +5     
==========================================
+ Hits         7220     7232      +12     
  Misses        183      183              
- Partials      248      249       +1     

Flag	Coverage Δ
#unittest	94.36% <94.28%> (-0.01%)	⬇️

Impacted Files	Coverage Δ
...ackages/eslint-plugin/src/rules/member-ordering.ts	98.46% <94.28%> (-0.69%)	⬇️

[bradzacher]

lgtm - thanks for this!
please fix up the merge conflict and we can merge this

[miluoshi]

lgtm - thanks for this!
please fix up the merge conflict and we can merge this

Done. Thanks for the review!

[bradzacher]

@miluoshi - FYI your merge introduced formatting errors

[miluoshi]

@bradzacher Yes, I've noticed it and fixed it with the last commit, but I'm not sure why the Code style check still fails. I ran the format-check script locally and it passed.