core: Add sending device's credential to remove
core: Add sending device's credential to remove

This patch sends device's credential instead of owner's credential. It fix
potential security risks where a device could use UUIDs of other devices.
Another reason for this change is that owner concept is being deprecated
in meshblu.

CESARBR/knot-service-source,CESARBR/knot-service-source,CESARBR/knot-service-source,CESARBR/knot-service-source,CESARBR/knot-service-source