Review changes to UserSettingsPage

 - Switch to {} widget initialization
 - set fixed size on the Toggles so they don't scale down vertically
 - add another setting section for INTERFACE
 - add a placeholder value for deviceFingerprintValue_ so it can calculate the right size.
 - fix warnings about `QLayout: Attempting to add QLayout "" to UserSettingsPage "",` in boxWrap
 - hide widgets properly in Q_OS_MAC
 - remove mainLayout_ completely
 - clean up resizeEvent