ADD support for all versions of react

[ndelangen]

• manager will always use 1 version we control
• users can not install any version of react
• users can now specify a react alternative inmodule.resolve webpack config

[codecov]

Codecov Report

Merging #4808 into next will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             next    #4808   +/-   ##
=======================================
  Coverage   35.55%   35.55%           
=======================================
  Files         560      560           
  Lines        6809     6809           
  Branches      911      911           
=======================================
  Hits         2421     2421           
  Misses       3912     3912           
  Partials      476      476

Impacted Files	Coverage Δ
.../core/src/server/manager/manager-webpack.config.js	0% <ø> (ø)	⬆️

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