feat(eslint-plugin): [require-await] add --fix support

[nevir]

This adds --fix support for the require-await rule.

[typescript-eslint]

Thanks for the PR, @nevir!

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!

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[codecov]

Codecov Report

Merging #1561 into master will decrease coverage by 0.02%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #1561      +/-   ##
==========================================
- Coverage   95.55%   95.52%   -0.03%     
==========================================
  Files         142      142              
  Lines        6596     6621      +25     
  Branches     1887     1895       +8     
==========================================
+ Hits         6303     6325      +22     
  Misses        106      106              
- Partials      187      190       +3     

[bradzacher]

a few comments, mostly LGTM.

[nevir]

Thanks for the review 👍 updated

[nevir]

Oh, ASI, how I love you ><

[bradzacher]

LGTM - thanks for adding this!

[nevir]

Awesome, thanks!

[yangmingshan]

But this PR is add --fix support for the return-await rule, not require-await. Release log is also wrong.