Fix XCT fails build in F# projects (#1133)

* Add "shared" to file name

* Revert "Add "shared" to file name"

This reverts commit 8760ddd.

* Include PreserveXamarinCommunityToolkit only in csproj

* Add PreserveXamarinCommunityToolkit.fs

* Resolve comments

* Revert "Resolve comments"

This reverts commit 7be495f.

* Revert "Add PreserveXamarinCommunityToolkit.fs"

This reverts commit 403f20c.

Co-authored-by: Brandon Minnick <[email protected]>

Author: maxkoshevoi

src/CommunityToolkit/Xamarin.CommunityToolkit/build/Xamarin.CommunityToolkit.targets

@@ -1,6 +1,7 @@
 <Project>
   <ItemGroup>
-    <Compile Include="$(MSBuildThisFileDirectory)PreserveXamarinCommunityToolkit.cs"
+    <Compile Condition="'$(MSBuildProjectExtension)' == '.csproj'" 
+             Include="$(MSBuildThisFileDirectory)PreserveXamarinCommunityToolkit.cs"
              Visible="false" />
   </ItemGroup>
 </Project>