Fix setting breakpoints with self versioned documents

[davidwengier]

Fixes an issue found in app building. Thanks @phil-allen-msft!

Also fixes #9161

To make reviewing easier:

• First commit is entirely mechanical cleanup, renames, etc. and can be skipped.
• Second commit is the fix.
• Third commit is tests.
• Fourth commit is updating more tests because these days when you ask VS to build things it doesn't build all of it and I need to get into the habit of doing a command line build before pushing

Because of the type and file renames, looking at the PR as a whole is inadvised.

[DustinCampbell]

Looks great! Thanks for cleaning up those abstract classes. I've been meaning to do that forever but haven't had the opportunity. 👍