Add tests to verify linked modules work

Created by: Timer

We're about to add support for linked modules. First, however, we need to add test cases.

Essentially, we want to add tests for a couple cases and validate these work in the test, dev, and production environment:

• link to a package with newly introduced dependencies
• link to a package which specifies peer deps in our main project, barring installed dev dependencies (maybe covered by below case)
• Use required webpack loader only in cra project but missing from linked dep