Controls: Rewrite UnitTextBox as extension of TextBox instead of UserControl

Elwig/Windows/ChartWindow.xaml

@@ -29,6 +29,15 @@
             <Setter Property="Height" Value="25"/>
             <Setter Property="TextWrapping" Value="NoWrap"/>
         </Style>
+        <Style TargetType="ctrl:UnitTextBox">
+            <Setter Property="HorizontalAlignment" Value="Stretch"/>
+            <Setter Property="VerticalAlignment" Value="Top"/>
+            <Setter Property="FontSize" Value="14"/>
+            <Setter Property="Padding" Value="2"/>
+            <Setter Property="IsReadOnly" Value="True"/>
+            <Setter Property="Height" Value="25"/>
+            <Setter Property="TextWrapping" Value="NoWrap"/>
+        </Style>
         <Style TargetType="ComboBox">
             <Setter Property="IsEnabled" Value="False"/>
             <Setter Property="Height" Value="25"/>