feat(eslint-plugin): [no-empty-function] add decoratedFunctions option

[a-tarasyuk]

Fixes #2278

[typescript-eslint]

Thanks for the PR, @a-tarasyuk!

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 #2295 into master will decrease coverage by 0.01%.
The diff coverage is 84.61%.

@@            Coverage Diff             @@
##           master    #2295      +/-   ##
==========================================
- Coverage   93.12%   93.10%   -0.02%     
==========================================
  Files         283      283              
  Lines        9057     9069      +12     
  Branches     2482     2489       +7     
==========================================
+ Hits         8434     8444      +10     
  Misses        301      301              
- Partials      322      324       +2     

Flag	Coverage Δ
#unittest	93.10% <84.61%> (-0.02%)	⬇️

Impacted Files	Coverage Δ
...kages/eslint-plugin/src/rules/no-empty-function.ts	83.78% <84.61%> (-0.22%)	⬇️

[bradzacher]

ezpz.
thanks for your contribution!