Helper function to generate stub files used for tests

[johlju]

I want to place the helper function I put together somewhere. The helper function loads the module and generates a file containing stubs for all cmdlets.
I want to place it in the resource somewhere so that others can generate these stubs as well.

I suggest to put it under the Stubs folder in a separate .ps1 file. I will send in a PR for that. But I'm happy to move it anywhere that we decide is more suitable.