Fix issue: DatePicker adds the ButtonPosition setting to determine the left and right position of the icon （#223 ） 💯

Author: yanjinhuagood

src/WPFDevelopers.Shared/WPFDevelopers.Shared.projitems

@@ -62,6 +62,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Controls\PathIcon\PackIconKind.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Controls\PathIcon\PathIcon.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Core\Converts\BreadCrumbBarConverter.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Core\Converts\ButtonPositionToColumnConverter.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Core\Converts\ColorConverter.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Core\Converts\ColorTypeToVisibilityConverter.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Core\Converts\CornerRadiusToSurroundConverter.cs" />