ProjectExplorer: Give build systems a name

... and make it accessible through a variable.

Fixes: QTCREATORBUG-26147
Change-Id: I0601c09a74360b91fe8421876207a8f4ae9d75b6
Reviewed-by: hjk <hjk@qt.io>

src/plugins/compilationdatabaseprojectmanager/compilationdatabaseproject.h

@@ -64,6 +64,7 @@ public:
     ~CompilationDatabaseBuildSystem();
 
     void triggerParsing() final;
+    QString name() const final { return QLatin1String("compilationdb"); }
 
     void reparseProject();
     void updateDeploymentData();