Static web assets SDK support for multi targeting conventions

[javiercn]

Update Static Web Assets to account for multitargeted projects.
The project needs to include the assets produced by the net8.0-browser TFM.
We need to handle the different TFM combinations here
We need to do work to support multi-targeting during build and publish.

For the conventions see https://learn.microsoft.com/en-us/dotnet/maui/platform-integration/configure-multi-targeting?view=net-maui-7.0

[ghost]

Thanks for contacting us.

We're moving this issue to the .NET 8 Planning milestone for future evaluation / consideration. We would like to keep this around to collect more feedback, which can help us with prioritizing this work. We will re-evaluate this issue, during our next planning meeting(s).
If we later determine, that the issue has no community involvement, or it's very rare and low-impact issue, we will close it - so that the team can focus on more important and high impact issues.
To learn more about what to expect next and how this issue will be handled you can read more about our triage process here.

[javiercn]

Initial cut here

Missing gaps:

• Conflict resolution for scoped css: We need to figure out what we do here. We don't want to embed the app bundle Project.styles.css. We want to keep platform specific styles (for example, if a component is defined inside the Browser folder) so we want to get the project bundle for it and merge it into the main app bundle in the embedding TFM.
• Conflict resolution for JS modules: There's likely no conflict as long as we don't do any rename.
• Conflict resolution for JS initializers: We need to pass in the initializers to the embedding TFM.
• Service worker
• Retrieve assets from embedded referenced projects: This is the case when the project is multitargeting and it has a project reference that is exclusive to the embedded target. For example, a project A that multitargets net8.0;net8.0-browser and there is a project reference to project B that only applies to net8.0-browser.
• Retrieve package assets from embedded referenced packages: This is the case when the project is multitargeting and it has a package reference that is exclusive to the embedded target. For example, a project A that multitargets net8.0;net8.0-browser and there is a package reference to package B that only applies to net8.0-browser.

[javiercn]

#49074