5513: Try figure out correct workspace in vscode multi root workspace r=vsrs a=urbandove
the code to replace the root with the `${workspaceRoot}` arg breaks in multi root workspaces as it needs a qualifier `${workspaceRoot:workspaceName}`
This PR attempts to figure out the root workspace - and if it cant find it falls back to the first workspace
Co-authored-by: Urban Dove <urbandove80@gmail.com>