[Maps] Add Windows map handler based on Webview

[rmarinho]

Description of Change

This is the initial work to support the Map feature on Windows, since there's no official MapControl yet on WinUI we provide this webview based implementation for now.

Fixes: #605

PR Checklist

• [ ] Has a linked Issue, and the Issue has been approved(bug) or Championed (feature/proposal)
• [ ] Has tests (if omitted, state reason in description)
• [ ] Has samples (if omitted, state reason in description)
• [ ] Rebased on top of main at time of PR
• [ ] Changes adhere to coding standard
• [ ] Documentation created or updated: https://github.com/MicrosoftDocs/CommunityToolkit/pull/XYZ

Additional information

[TheCodeTraveler]

Thanks Rui! Could you first please submit a New Feature Proposal.

Once you've submitted a Proposal, we will vote to approve adding the new feature to the .NET MAUI Community Toolkit.

Here's some more information on the process:

• Submitting a new feature
• Contributing to .NET MAUI Toolkit

[TheCodeTraveler]

Closing this PR until Proposal has been approved

[bijington]

The proposal has been approved 🥳

[JORGEGO]

.NET MAUI Maps it is a critical piece... I believe Microsoft should support have a solution for thousand of apps developed in Xamarin Forms for UWP and use Xamarin forms map and want to migrate to MAUI...