Core: attach view configuration (#377).

BREAKING CHANGES

ViewConfiguration public API:
    - getConfigTopics() returns attached topics (instead of topic models)
    - getConfigTopic() is dropped
    - updateConfigTopic() is new method

DeepaMehtaObjectModel public API:
    - set(DeepaMehtaObjectModel model) is new method

In preparation of #377 (workspace assignments for standard type's view configurations).

See ticket 377.