Port away from most cases of Q_FOREACH to C++11 ranged for loop.

In order to avoid deep copies, Qt containers over which we iterate must be const
The remaining unported cases require qAsConst (Qt 5.7) or std::as_const (C++17)

src/modules/partition/core/PartitionCoreModule.h

@@ -127,7 +127,7 @@ public:
 
     void dumpQueue() const;
 
-    OsproberEntryList osproberEntries() const;
+    const OsproberEntryList osproberEntries() const;
 
 Q_SIGNALS:
     void hasRootMountPointChanged( bool value );