add support for Jest's moduleNameMapper configuration

[nareshbhatia]

Allow merging of external moduleNameMapper configuration with the internal configuration required by react-scripts.

Fixes #4262

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[nareshbhatia]

@iansu, just curious, what are the next steps to approving and merging this PR?

[nareshbhatia]

Requesting an update on this PR. This is the only critical issue that is preventing my company to move from create-react-app-ts to CRA.

TIA

[cubabit]

Looking forward to this getting merged and released!

[mrmckeb]

@nareshbhatia I'm discussing this with @iansu - we have been hard at work at 3.0, and then I think we can take a look at this for you.

[nareshbhatia]

Thanks for the update, @mrmckeb. Waiting eagerly :-)

[ponciusz]

any progress with that??

[nareshbhatia]

As far as I can tell, this change has been implemented in code. If yes, this PR can be closed.

Note that the docs are still out-of-sync, moduleNameMapper is not included as a supported tag.

[ianschmitz]

Already fixed by #6055.