VS Code "Problems" view does not update when a QL file is deleted

[lcartey]

Describe the bug
If I create a QL file with some compilation errors, those compilation errors will be reported in the standard VS Code "Problems" view. However, if I delete those QL files without resolving the compilation errors, the "Problems" view is not updated to remove the old compilation errors.

To Reproduce

1. Create a QL file with a compilation error.
2. Observe that the compilation error appears in the "Problems" view
3. Delete the QL file
4. Observe that the compilation errors are still present in the "Problems" view

Expected behavior
Remove all "Problems" for QL files after deleting the file.

Additional context
Add any other context about the problem here.