Add #include "file.h" is incorrectly suggested instead of <file.h> for subDir/file.h

[sean-mcmanus]

See the screenshot -- test2 is on the includePath and the current file is at the root, so it should be suggesting <file.h> since file.h is not in the same folder as the source file.

The issue in inherited from Visual Studio (shared code).

It was found after adding a test case for #11989