API changes from Capella 1.1.x/1.2.0 to 1.2.x

Since Capella 1.2.1, uid should be used to identify a representation (diagram/table) instead of xmiid. The convenient class org.polarsys.capella.shared.id.handler.IdManager which is used to obtain an EObject from its id and vice versa has been implemented to take into account representation's uid. Consumers of this class should not have any impact on existing code. Otherwise, one should migrate their code to use this class when trying to obtain a representation from its id and vice versa.
A migration of Capella 1.1.x/1.2.0 models is needed to update representations' uid based on their xmiid. This assures that references to representations via their xmiids in previous versions still work in migrated models.