Clang: Locator: Add filters for classes, includes, functions

Filters are based on symbol query where they are
not implemented yet.

Change-Id: Id826beaf6bb47a81363c36780d7254a85a9a3cc9
Reviewed-by: Marco Bubke <marco.bubke@qt.io>

src/plugins/clangrefactoring/symbolqueryinterface.h

@@ -30,6 +30,7 @@
 #include "class.h"
 #include "enum.h"
 #include "function.h"
+#include "include.h"
 #include "symbol.h"
 
 #include <cpptools/usages.h>
@@ -39,7 +40,8 @@ namespace ClangRefactoring {
 enum class SymbolType
 {
     Class = 0,
-    Enum = 1
+    Enum = 1,
+    Include = 2
 };
 
 class SymbolQueryInterface