ProjectExplorer: De-QObject-ify BuildConfigurationFactories

The QObject was not heavily used. Object name was for debugging only,
translation context can be taken from the corresponding BuildConfiguration
objects, the qobject_casts in the three big importers are replaced by
dynamic_cast, which is good enough in that context.

Take the opportunity to re-use translations from base BuildConfiguration
for the common cases and sprinkle in some 'final'.

Change-Id: I8e9727c98c6e943cb333556861c24e701c2bdf45
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/plugins/compilationdatabaseprojectmanager/compilationdatabaseproject.h

@@ -94,10 +94,8 @@ public:
     CompilationDatabaseEditorFactory();
 };
 
-class CompilationDatabaseBuildConfigurationFactory
-    : public ProjectExplorer::BuildConfigurationFactory
+class CompilationDatabaseBuildConfigurationFactory : public ProjectExplorer::BuildConfigurationFactory
 {
-    Q_OBJECT
 public:
     CompilationDatabaseBuildConfigurationFactory();
 };