At some point in recent history, our ProjectSystem VSIX picked up a bunch of unexpected files (see #6612). It took us a while to notice this, at which point it was unclear which change caused this to regress.
This commit adds the current list of files as a text file that is under version control. There is one file per VSIX (we have three). Any addition or removal from a VSIX will cause a unit test to fail, which will draw our attention to the change immediately. If the change is intentional, we need only update a text file. If not, we can investigate immediately and block merging a regression.
Drew Noakes