Make `makeCustomWrappedIt` wrapper for mocha extensions.
Make `makeCustomWrappedIt` wrapper for mocha extensions.

This CL provides a foundation for enabling custom test `it` functions in
a way that will ensure they can still be used with `.only`, `.skip` and
so on.

Bug: chromium:1186163
Change-Id: I31544ad5dd0cf86132a2b59c910da0a27acfca17
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/3162063
Reviewed-by: Alex Rudenko <d8d88e7d7e77f69e23d1d1432231196fb8e02a62@chromium.org>
Commit-Queue: Jack Franklin <993fcadce4d04090da2fefd557a0995e7966c8d5@chromium.org>

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