Pull out `@salesforce` import transforms not relevant to OSS

[trevor-bliss]

In a test, the @salesforce scoped module imports will be automatically transpiled to provide a default value since the actual value would require a connection to an active app.

For example, import myMethod from '@salesforce/apex/FooController.fooMethod' will be automatically transpiled to define myMethod and set it's value to some reasonable default. In this case, myMethod will be a function that returns a resolved Promise.

Most (all?) of these @salesforce imports are not relevant to people not devloping on the Salesforce platform. We should pull these transforms out into a separate project and only apply them when tests are run on the platform.

W-6834501

[pmdartus]

Agreed, all the @salesforce/ prefixed imports should be transformed by another transformer. In order to keep this project simple to maintain, what do you think about creating this transformer in this repository?

[trevor-bliss]

I don't mind keeping the additional transformer in this repo, though I know some imports may be internal only.

[CommanderQ]

Would I be correct in assuming that resolving this issue would also be related to enhanced support for the @salesforce/internal/* imports?