CppTools: Distinguish between ProjectFile::{unclassified,unsupported}

There was no way to determine whether ProjectFile::classify() was run or
not. Now, ProjectFile::classify() returns ProjectFile::Unsupported
instead of ProjectFile::Unclassified.

Change-Id: I660d0e42044bdefcac38058c6f4a3425983a6d93
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/modeleditor/componentviewcontroller.cpp

@@ -399,6 +399,7 @@ void ComponentViewController::createComponentModel(const ProjectExplorer::Folder
             isSource = true;
             break;
         case CppTools::ProjectFile::Unclassified:
+        case CppTools::ProjectFile::Unsupported:
             isSource = false;
             break;
         }