Utilize new StaticWebAssets SDK

[MackinnonBuck]

Splitting out some items from #46997 as follow-up items after the changes in dotnet/sdk#31079:

• Removing the Razor SDK and related files from the SDK repo, since they ship from dotnet/razor now.
• Removing Static Web Assets related files from the Razor SDK repo, since they'll ship from the SDK repo.
• Updating the Razor SDK repo to consume the static web assets SDK repo.

[mkArtakMSFT]

This issue was created with the assumption that all the Static Assets code lives in the dotnet/razor repo, but it's not the case. Hence, there is no work to be done here.