GH-338, GH-513, GH-700 Unify edit instance with console window

* The resulting instance window can be closed at any point.
* Main window is kept open and running instances are marked with a badge.
* Multiple instances can now run from the same MultiMC - it's even more **multi** now.
* MultiMC can be entirely closed, keeping Minecraft(s) running.

application/widgets/PageContainer.h

@@ -45,6 +45,8 @@ public:
 
 	virtual bool selectPage(QString pageId) override;
 
+	void refresh();
+
 private:
 	void createUI();
 private