Add support for yarn@v1 for the javascript backend

[tobni]

Is your feature request related to a problem? Please describe.
Some users might prefer yarn over npm, most likely because they're migrating a codebase.

Describe the solution you'd like
Users can pick a default package manager for the project in the nodejs subsystem. Users can also choose a particular package manager for different package_json targets (a nodejs resolve should require the same one for all, though).

Describe alternatives you've considered
Only support npm. Will make some adopters shy away

Additional context
Blocked on #18525