Cleanup account page

- Fix small padding on the right when they is not enough elements for a
  scrollbar to appear (possibly due to a kirigami regression)
- Move account editor to a seperate page
- Cleanup a bit the code style
- Add tooltip to toolbuttons

Signed-off-by: Carl Schwan <carl@carlschwan.eu>

imports/NeoChat/Settings/DevicesPage.qml

@@ -17,6 +17,8 @@ Kirigami.ScrollablePage {
             id: devices
         }
 
+        anchors.fill: parent
+
         Kirigami.PlaceholderMessage {
             visible: parent.model.count === 0 // We can assume 0 means loading since there is at least one device
             anchors.centerIn: parent