Resize dialog focus fixes

PixiEditor/Views/Dialogs/ResizeCanvasPopup.xaml

@@ -42,6 +42,7 @@
                               Width="240"
                               Height="170"
                               x:Name="sizePicker"
+                              Focusable="True"
                               ChosenHeight="{Binding NewAbsoluteHeight, Mode=TwoWay, ElementName=window}"
                               ChosenWidth="{Binding NewAbsoluteWidth, Mode=TwoWay, ElementName=window}" 
                               ChosenPercentageSize="{Binding NewPercentageSize, Mode=TwoWay, ElementName=window}"

PixiEditor/Views/Dialogs/ResizeDocumentPopup.xaml

@@ -37,6 +37,7 @@
         <local:SizePicker HorizontalAlignment="Center" Width="240" Height="180" Margin="0,30,0,0"
             x:Name="sizePicker"
             PreserveAspectRatio="True"
+                          Focusable="True"
             ChosenHeight="{Binding NewAbsoluteHeight, Mode=TwoWay, ElementName=window}"
             ChosenWidth="{Binding NewAbsoluteWidth, Mode=TwoWay, ElementName=window}" 
             ChosenPercentageSize="{Binding NewPercentageSize, Mode=TwoWay, ElementName=window}"