RBRenameMethodRefactoring does not use the cache when computing sender/implementors

[chisandrei]

This iterates over implementors/senders instead of using the cache.

refactoring := ( RBRenameMethodRefactoring
		renameMethod: #haba 
		in: Object 
		to: #haba2 
		permutation: #())

refactoring primitiveExecute

[girba]

In a plain GT:

[girba]

One solution is to hook an enhanced RBNamespace implementation in GtRenameController>>#createModel.

/cc @j-brant @refactoringdr

[girba]

With the default RBNamespace:

With GtRBNamespace: (implementers and references no longer appear )

[girba]

Enable the new implementation with:

RBClassModelFactory setRBNamespace: GtRBNamespace