rename config container extensions to avoid source server issues

Author: fsimonazzi

source/Unity.Configuration/Src/Unity.Configuration.csproj

@@ -146,7 +146,7 @@
     <Compile Include="ConfigurationHelpers\TypeResolverImpl.cs" />
     <Compile Include="UnityConfigurationSection.cs" />
     <Compile Include="ContainerElementCollection.cs" />
-    <Compile Include="UnityContainerExtensions.cs" />
+    <Compile Include="UnityContainerConfigurationExtensions.cs" />
     <Compile Include="ValueElement.cs" />
     <None Include="..\..\Unity.licenseheader">
       <Link>Unity.licenseheader</Link>