Add support for room shares to DeletedShareAPIController

In some cases, the DeletedShareAPIController requires explicit handling
of each type of share (for example, to format a share for a
DataResponse). Room shares are implemented in an external app (Nextcloud
Talk), so in order to keep the controller as isolated as possible from
room share specifics all that explicit handling is done in a helper
class provided by the Talk app.

In other cases it is just enough to call the share manager specifying a
room share type; note that the share manager is guarded against share
types for which there is no provider, so it is not necessary to
explicitly check that before passing room shares to the share manager.

Signed-off-by: Daniel Calviño Sánchez <danxuliu@gmail.com>