Add integration tests for macros

[DanTup]

It's difficult to do this before the work is in the server (and available without copies of _fe_shared etc.), but we should have a test that verified macros are working and that we can successfully perform something like Go-to-Definition into a macro file. Eg.:

• create a macro that adds a method
• use that macro on a class and call the method
• invoke Go-to-Definition and ensure the macro generated file is in the results
• open the macro-generated file by URI and ensure we read the contents of it
• modify the macro implementation to change the file contents
• ensure the editor updated with the new contents