CMakePM: Treat "Forms" and "State charts" as special source groups

Amends 76dcc069d6

As a user I expect that the "Forms" and "State charts" source groups
should go away if I select the filter "Hide Source and Header Groups" in
Projects view.

They are not meant to be user defined source groups.

Change-Id: I17db9eb7e1da17b93a45f6093782add19c2b5cb1
Reviewed-by: Marcus Tillmanns <marcus.tillmanns@qt.io>

src/plugins/cmakeprojectmanager/projecttreehelper.cpp

@@ -23,7 +23,8 @@ bool defaultCMakeSourceGroupFolder(const QString &displayName)
     return displayName == "Source Files" || displayName == "Header Files"
            || displayName == "Resources" || displayName == ""
            || displayName == "Precompile Header File" || displayName == "CMake Rules"
-           || displayName == "Object Files";
+           || displayName == "Object Files" || displayName == "Forms"
+           || displayName == "State charts";
 }
 
 std::unique_ptr<FolderNode> createCMakeVFolder(const Utils::FilePath &basePath,