fix(cli): Allow common custom scaffold template files

[esteban-url]

This PR fixes #11754 by adding the ability to generate test, stories and mock files when custom scaffold templates are in use.

Right now these files are not supported/generated even if a template file is there. This PR will allow a dev to define their own test, stories and mock templates for components and/or pages and have the yarn rw g scaffold [model] command correctly generate it for them.

Please let me know what you think of it and/or it any testing is required.

Thanks!

[Tobbe]

I like this addition. I just want to spend some time thinking about what unit tests, if any, can be added

[esteban-url]

thanks @Tobbe I gave it some though, but couldn't come up with any, so I thought better to ask the team. Also, this is "user land", and a somewhat "advanced" scenario, so they've already strayed out of the path, and have accepted that they're pretty much on their own, since they ejected the generators.

It's me, I'm "they" 😅

[Tobbe]

@esteban-url I added some tests. Please take a look and edit/add as you see fit. Another thing I realized is that now when you run yarn rw setup generator scaffold it should probably also spit out template test, mock, stories etc files as well. Can you please update the code to do that?