Add mocha trx reporter

[jessetrinity]

This open sources the mocha trx reporter dependency and publishes it to github packages for this repo. See https://github.com/microsoft/dev-tunnels/packages/1563273.

The ssh package also depends on this package. Once that has been open sourced in this repo as well, the vs package feed can also be removed.

[jasongin]

This is not a good way to handle a fork of an open-source package... The correct way should be to fork the original repo and then apply the differences. That way the changes can be easily diffed and ported back and forth between the two forks.

[jessetrinity]

This is not a good way to handle a fork of an open-source package... The correct way should be to fork the original repo and then apply the differences. That way the changes can be easily diffed and ported back and forth between the two forks.

If it was indeed a fork of mocha-trx-reporter then it was rewritten in TypeScript at some point and bears little resemblance. I don't even see the tests that the original has. Are we sure it was a fork of that repo and not just inspired by it (or a fork of some other repo)?

[jasongin]

Hmm, I didn't realize it had diverged that much.

Can we consider moving to junit reporting instead, as suggested here? Then we won't have to add all this extra code.