[rush] Provide an "install-run-rushx.js" script similar to "install-run-rush.js"

[poelstra]

It can be useful to run rushx start something in a CI environment.

There already is common/scripts/install-run-rush.js, but there's e.g. no rush run as an alias for rushx that would allow using rush to e.g. prepare bin paths.

Suggestion from @octogonz was to create common/scripts/install-run-rushx.js.

[octogonz]

This should be pretty easy to implement. I think it's a good idea.

@iclanton maybe you could give it to someone as an onboarding exercise. :-)

[bsiegel]

Completed in #1440, this issue can be closed 🎉

[apostolisms]

Closing since this completed here