Add subclass driver

[hernanmd]

This PR implements a first version of "Add subclass" refactoring as a driver:

https://github.com/pharo-project/pharo/assets/4825959/663878b5-19e6-4c7b-a0c8-bf097d2bab4a

Main features

• The Spec UI to add a new subclass (see video above).
• It checks and informs interactively if the class already exists.
• It checks invalid class names.
• Default class comment could be customized implementing blankCommentTemplate in the class selected as superclass.

Implementation notes

• A RBAddNewClassRefactoring which differs from the Insert New Class refactoring in that does not reparent the subclasses to the new class.
• The driver implementation in ReAddSubclassDriver and ReAddSubclassDriverTest.

Known issues

• CmdCommandAborted signal and CmCommandAborted signal are failing right now and it should be investigated why (debugger keep opening which could mean the exception is not properly handled).
• Next version will include more tests.