misused `anchors.fill` in LayerStack, StatusPage and HandWritingKeyboard

[dodoradio]

These elements set anchors.fill, which makes them impossible to use in columns and other elements which break when anchors are used.
It seems that a lot of our apps are written with these assumptions in mind, so they will all need to have these anchors explicitly fixed before this can be patched out of qml-asteroid

[beroset]

Can you provide an example that shows the problem? That will make it easier to both understand exactly the problem and to verify it once it's fixed.