Update Microsoft.Data.SqlClient to 4.0.0 (#58)

Author: SergeiPavlov

Orm/Xtensive.Orm.SqlServer/Xtensive.Orm.SqlServer.csproj

@@ -15,7 +15,7 @@
     <WarningLevel>2</WarningLevel>
   </PropertyGroup>
   <ItemGroup>
-    <PackageReference Include="Microsoft.Data.SqlClient" Version="3.0.1" />
+    <PackageReference Include="Microsoft.Data.SqlClient" Version="4.0.0" />
   </ItemGroup>
 
   <ItemGroup>