ux: use tabular numbers for commit time

Author: ChiahongHong

src/Views/Histories.axaml

@@ -218,6 +218,7 @@
               <DataTemplate DataType="m:Commit">
                 <Border Padding="8,0" Background="Transparent" ClipToBounds="True">
                   <v:CommitTimeTextBlock FontWeight="{Binding IsCurrentHead, Converter={x:Static c:BoolConverters.IsBoldToFontWeight}}"
+                                         FontFeatures="+tnum"
                                          Opacity="{Binding IsMerged, Converter={x:Static c:BoolConverters.IsMergedToOpacity}}"
                                          Timestamp="{Binding CommitterTime, Mode=OneWay}"
                                          ShowAsDateTime="{Binding Source={x:Static vm:Preferences.Instance}, Path=!DisplayTimeAsPeriodInHistories, Mode=OneWay}"