Enable installing binaries from multiple domains

Related: https://github.com/dotnet/vscode-dotnet-runtime/issues/2121
Blocking: https://github.com/dotnet/core/pull/9724

The following are safe domains:

- `download.visualstudio.microsoft.com`
- `builds.dotnet.microsoft.com`

This code needs to change:

https://github.com/dotnet/vscode-dotnet-runtime/blob/674f3683c5d01d48583bc5c3624a2559cc32866c/vscode-dotnet-runtime-library/src/Acquisition/GlobalInstallerResolver.ts#L250-L255

I'm hoping we can target this change for 2.2.8. I'd propose merging the PR above one week after the extension was released. After a week, we're likely well into the long tail.