feat(config): add support for multiple paths in module name mapper

[OrkhanAlikhanov]

Summary

Closes #1072

Does this PR introduce a breaking change?

• Yes
• No

[coveralls]

Pull Request Test Coverage Report for Build 4990

• 4 of 4 (100.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.004%) to 92.822%

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Totals
Change from base Build 4988:	0.004%
Covered Lines:	1065
Relevant Lines:	1100

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💛 - Coveralls

[ahnpnl]

hi, thank you for your PR. In general the PR LGTM.

Just extra requests:

• Would you please add extra tests to e2e ? In e2e, there are e2e tests as well as tests on external repos. I think this kind of feature deserves some e2e tests.

• Would you please adjust documentations about the usage of this function pathToModuleNameMapper as well ? You can find documentations in docs/user/config/index.md

[OrkhanAlikhanov]

I have no idea how an e2e test should look like. Also I don't think there is any need for updating docs because it never explained the method's implementation details.

[ahnpnl]

You can put the example of using this function in external-repos. In that folder, there are several independent projects. You can adjust one project to have this function in use. That would be sufficient enough.

To test the changes in external-repos, you can run test:external-repos script which can be found in package.json

Regarding to documentation, it can be excluded from this PR.

[OrkhanAlikhanov]

I added e2e tests, thanks for guiding me. Also rebased the master. I hope it passes the quality control this time :]

[ahnpnl]

thanks 👍 LGTM
@kulshekhar please have a look once

[kulshekhar]

Looks good to me as well. Thanks @OrkhanAlikhanov 😃