Fixes the following in RegisterXamlComponentRecursive method (called for example on Paste):

- Getting the correct namescope for RootItem (the INameScope case was not checked).

- Clears the local namescope for the object if it exists, otherwise name changes will be registered in the local namespace instead of RootItem document namespace.

- Only adds _Copy (or CopyX, where X is an integer) if the previous name did not already end with _Copy. This prevents names as "myname_Copy_Copy_Copy..." to occur when copying and pasting already copied elements.

- Registers the new name to the RootItem namescope, only setting site.Name is not enough as its not yet a part of the RootItem document namescope.
Added test for testing generated names for pasted element copies and that the new names is registered in the correct namescope.
Removes namespace attributes from child nodes in the pasted snippet if they are already present in the root where the snippet is pasted.
Added a test "PasteCustomControlUsingMixedTypes" that failed before this fix.
Fixed type resolve when pasting a custom control using StaticResource.
Merge remote-tracking branch 'origin/NamescopeFixes'
Merge remote-tracking branch 'origin/WpfDesignerPasteFixes'

Conflicts:
	src/AddIns/DisplayBindings/WpfDesign/WpfDesign.Designer/Tests/Designer/EditOperationTests.cs