message: Add popup opening animation for autocomplete fields (win)
diff: <Popup Name="popup" x:FieldModifier="private"
  AllowsTransparency="True"
  HorizontalOffset="-8"
  - StaysOpen="False">
  + StaysOpen="False"
  + PopupAnimation="{DynamicResource {x:Static SystemParameters.ComboBoxPopupAnimationKey}}">
  <Grid Background="Transparent">
  <Border Margin="8 0 8 8"
  BorderBrush="{DynamicResource Toggl.PopupBorderBrush}"
  