Validate match of all session channel's UUID

Add a validation at channel creation to ensure that the uuid of all
channels created within a session match.

Note that we still need to keep a copy of the uuid field in the channel
private data at this stage, because the consumer daemon creates channels
with a NULL session pointer.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I3490bab8879ffa66bc1e19559b0a1a60d33d605b