Creates a local resource provider for a given Page or Template Resource.

We'll create local resources by application relative names. This routine gets passed a full virtual path to the page or template control and we'll strip off the virtual and use only the virtual relative path.

So: /myapp/test.aspx becomes test.aspx and /myapp/subdir/test.aspx becomes subdir/test.aspx

for our ResourceSet naming of local resources. The provider is created with this ResourceSet name.

public virtual IResourceProvider CreateLocalResourceProvider(string virtualPath)