Feature: Paste as Link

[davkean]

Summary:
Legacy supports pasting files as Linked files, CPS does not.

Steps to Reproduce:

1. Create two projects
2. In one project, rename Program.cs -> Program2.cs
3. Copy Program2.cs
4. Select the other project, and choose Edit

Expected Behavior:

Actual Behavior:
Paste As Link is not available
User Impact:

[davkean]

This is now, and will be available in a future Visual Studio insiders.