Convert netconf-util, netconf-ssh, netconf-tcp to blueprint

Convert netconf-util, netconf-ssh, netconf-tcp to blueprint

netconf-util, netconf-ssh, and netconf-tcp still used a BundleActivator
and accompanying ServiceTracker for service instantiation.  netconf-ssh
and netconf-tcp depend on netconf-util for NetconfConfiguration, so it
was decided to do the conversion of all three bundles in one patch.

netconf-util utilizes blueprint-cm to instantiate NetconfConfiguration
based on the ManagedService identified by the "netconf" PID.

Tests that were aimed at testing bespoke Activator logic were removed,
since the accompanying Activators were removed.  ServiceTrackers were
removed in favor of bean references.  Scaffolding used to locate the
NetconfConfiguration ManagedService was also removed since it is now
directly referenced using blueprint.

JIRA: NETCONF-510
Change-Id: I27452ea509bc50333ffc00c6d1d8de3133e8b850
Signed-off-by: Ryan Goulding <ryandgoulding@gmail.com>
Signed-off-by: Robert Varga <robert.varga@pantheon.tech>
(cherry picked from commit 7072e63a98485bbbfa686a639d28002377972aa0)