Organize mass-scale migration

Once the DescriptorRegistry has been consolidated and migration is a mastered and documented process, we could try to organize an event where every voluntary from dev or ps teams, dedicate some time to migrate some modules.

To prepare this step, making all current descriptors extend the new Descriptor interface could be done programmatically, removal of registries and potential adaptation of the component implementations will have to be by humans as it's logic matter.