chore(fork-rac): fork react async component for specific usage

[cbazureau]

• Use required chunkName
• Use chunkName instead of incremental id Goal is to use SASS/css chunking and not only JS chunking by using a modified extract-text-webpack-plugin + a syntax like this :

  const MyComponentChunk = asyncComponent({
  chunkName: 'my-component',
  resolve: () => import(/* webpackChunkName: "my-component" */ '../path/MyComponent'),
  });

[codecov[bot]]

Codecov Report

Merging #73 into master will decrease coverage by 0.4%. The diff coverage is 100%.

@@            Coverage Diff             @@
##           master      #73      +/-   ##
==========================================
- Coverage   94.38%   93.97%   -0.41%     
==========================================
  Files           3        3              
  Lines          89       83       -6     
  Branches       25       24       -1     
==========================================
- Hits           84       78       -6     
  Misses          5        5

Impacted Files	Coverage Δ
src/asyncComponent.js	92.64% <100%> (-0.32%)	:arrow_down:
src/createAsyncContext.js	100% <100%> (ø)	:arrow_up:
src/AsyncComponentProvider.js	100% <100%> (ø)	:arrow_up:

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