avalonia: fixed sizing of numericupdown

InABox.Avalonia/Theme/Classes/NumericUpDown.axaml

@@ -0,0 +1,7 @@
+<Styles xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+		xmlns:components="using:InABox.Avalonia.Components">
+	<Style Selector="NumericUpDown">
+		<Setter Property="MinWidth" Value="0"/>
+	</Style>
+</Styles>

InABox.Avalonia/Theme/Styles.axaml

@@ -10,6 +10,7 @@
 	<StyleInclude Source="/Theme/Classes/Image.axaml" />
 	<StyleInclude Source="/Theme/Classes/Label.axaml" />
 	<StyleInclude Source="/Theme/Classes/ListBox.axaml" />
+	<StyleInclude Source="/Theme/Classes/NumericUpDown.axaml" />
 	<StyleInclude Source="/Theme/Classes/Separator.axaml" />
 	<StyleInclude Source="/Theme/Classes/TabItem.axaml" />
 	<StyleInclude Source="/Theme/Classes/TabStrip.axaml" />