Rationalise logic of synchronisation between transport, attribute and handler #154
Description
The current synchronisation of values between an attribute, its handler and its representation in the transport layer is incorrect and the methods are named inconsistently.
AttrW.update_display... should be moved to AttrRW - there is no value to update from the Attribute for an AttrW
This WIP diagram describes the logic: https://link.excalidraw.com/l/7igwo1LrqWY/9ogO8dgeY46