bgpd: Allow `network XXX` to work with bgp suppress-fib-pending

bgpd: Allow `network XXX` to work with bgp suppress-fib-pending

When bgp is using `bgp suppress-fib-pending` and the end
operator is using network statements, bgp was not sending
the network'ed prefix'es to it's peers.  Fix this.

Also update the test cases for bgp_suppress_fib to test
this new corner case( I am sure that there are going to
be others that will need to be added ).

Fixes: #12112
Signed-off-by: Donald Sharp <sharpd@nvidia.com>
(cherry picked from commit 4801fc4670020406fc609dedabc7482d88e3b656)