spike/add-support-for-test-target

[spqw]

Resolves discussion https://github.com/tuist/tuist/discussions/4837

Short description 📝

Work in progress to evaluate how to add support for test targets

How to test the changes locally 🧐

Introducing testMap_whenTestTarget (not passing for now) - We're trying to make it go green

Checklist ✅

• The code architecture and patterns are consistent with the rest of the codebase
• The title of the PR will be used as changelog entry, please make sure it is clear and suitable
• In case the PR introduces changes that affect users, the documentation has been updated
• Contributors have checked that, if needed, the PR includes the label changelog:added, changelog:fixed, or changelog:changed