zebra: standardize ZAPI message handler args

zebra: standardize ZAPI message handler args

A lot of the handler functions that are called directly from the ZAPI
input processing code take different argument sets where they don't need
to. These functions are called from only one place and all have the same
fundamental information available to them to do their work. There is no
need to specialize what information is passed to them; it is cleaner and
easier to understand when they all accept the same base set of
information and extract what they need inline.

Signed-off-by: Quentin Young <qlyoung@cumulusnetworks.com>