fix: Add the ability to disable Windows extensions generation

[jeromelaban]

PR Type

What kind of change does this PR introduce?

• Bugfix

What is the new behavior?

Adds the ability to disable the generated windows extensions. Used when building with UWP inside the uno solution.

PR Checklist

Please check if your PR fulfills the following requirements:

• Tested code with current supported SDKs
• Docs have been added/updated which fit documentation template. (for bug fixes / features)
• Unit Tests and/or UI Tests for the changes have been added (for bug fixes / features) (if applicable)
• Wasm UI Tests are not showing unexpected any differences. Validate PR Screenshots Compare Test Run results.
• Contains NO breaking changes
• Updated the Release Notes
• Associated with an issue (GitHub or internal)

Other information

Internal Issue (If applicable):

[pictos]

It looks good to me, I've one question regarding the implementation but it doesn't invalidate the PR