Don't pass a domainObject instance into mct-representation
until a view for that specific domainObject is available;
this avoids ordering issues where a new domainObject is
passed briefly to controllers in represented views before
a event is issued, which can result in undesired
behavior for views that need to manage resources (such as
the subscriptions used to support telemetry retrieved
from the WARP Server, WTD-644.
Refactor view switcher to simplify it; treat it
as a representation of a domain object that modifies
an ng-model. This simplifies reuse, e.g. in frames
within a layout. WTD-535.