Port away from HeaderFooterToolbar
When I created this component, I didn't know that the QQC2 `ToolBar` component can do all the same things and even has built-in support for being displayed as a header or a footer. So let's use that instead.
When I created this component, I didn't know that the QQC2 `ToolBar` component can do all the same things and even has built-in support for being displayed as a header or a footer. So let's use that instead.