Data storage (i.e. extension and registered root path) for version control extensions inside Dev Home

[ssparach]

Summary of the pull request

This PR contains the changes required to store and retrieve data from a json file required for source control integration.

References and relevant issues

Detailed description of the pull request / Additional comments

The code changes included are:

• Read/Write extension, root path pairs (JSON file)
• Temporary UI (the UI currently outlined in this PR will be removed and is in place currently to provide basic add functionality). The new UI will be in accordance to design specifications and is being tracked.
• Unit Test

Validation steps performed

PR checklist

• Closes #xxx
• Tests added/passed
• Documentation updated

[dhoehna]

NIT: Change the error message based on what is being checked. Give the user the exact reason why the path isn't valid.

[DefaultRyan]

NIT: Change the error message based on what is being checked. Give the user the exact reason why the path isn't valid.

+1 to this. We may even consider having some different error/exception types for path checking.

Once interesting example is that repositories mounted on WSL look sorta like UNC paths, but we should try to detect that case separate from UNC paths. Also with WSL repos, their file ownership looks off from Windows' point of view, so Git will raise specific errors about those cases. Rather than outright failing, we should offer a suggestion to the user to help them enable Git to work with those WSL repos, aka git config --global --add safe.directory <path to repo>

[ssparach]

Sounds great! Currently, the UI in place is temporary. I will incorporate this feedback and gain more clarity around the design for surfacing user facing error messages in the expected UX.