* Clean up string resources, use Arcade resx generator

* CodeLens resources


* Use NET20 instead of NETFX20

Part of https://devdiv.visualstudio.com/DevDiv/_workitems/edit/1065328

We suppressed these because we were on the .NET Portable profile and
thus couldn't do the anything else. We're no longer on the portable
profile.

* AssetProvider refactoring

* Remove usage of SessionWithSolution

* Move Razor specific service base