Add Web Platform-Target (Like React Native Web)

### Description

Scenario: I have build this super cool maui app which runs on iOS, Android, Windows and mac which is very successful. But now I notice for a lot of users it is an entry barrier to download and install the App.
It would be really cool to have an WebApp, which they could test-drive and then download the actual app.

Or I want to build something like WhatsApp Web or Spotify Web

If I have Ionic I can quickly just host my app on a webpage, since everything is HTML anyway.
If I have React Native, I "just" need to make it compatible with React Native Web.
If I have UNO I can run in the Web for the start.
If I have Flutter, I can use Flutter Web

If I have Maui I currently need to rewrite the whole app in Blazor or Simular. Or would need to convert to Blazor Hybrid, which would loose the Advantage of Native Controls.

Since I have all these controls which can render as Windows Controls, iOS Controls and Android Controls, why can't I build a renderer under WebAssembly and Html+Css for these controls?

Now I am a big fan of Blazor and Blazor Hybrid, but sometimes I just want the advantages of Native Apps. Also I don't see this as an competitor to Blazor, its just a very good complimentary option for Blazor and even better with Blazor Hybrid.

### Public API Changes

- Add a Plattform Target for WebAssembly/Blazor which renders the controls as HTML/CSS.

- Maybe Utilize even PWA functionalities

### Intended Use-Case

Make a Web Version of an already successfull App without having to rewrite.