Implement section headers

I'm not real happy with the limitations I had to work with here. The TableView can only accept a table of strings, so I basically had to fit everything into editing this dictionary of strings. Not the best. But it's very effective.

Contributes to issue CURA-8686.

resources/qml/ProfileOverview.qml

@@ -41,4 +41,5 @@ Cura.TableView
         TableModelColumn { display: "unit" }
         rows: qualitySettings.items
     }
+    sectionRole: "category"
 }