zebra: Use zebra dplane for RTM link and addr

zebra: Use zebra dplane for RTM link and addr

a) Move the reads of link and address information
into the dplane
b) Move the startup read of data into the dplane
as well.
c) Break up startup reading of the linux kernel data
into multiple phases.  As that we have implied ordering
of data that must be read first and if the dplane has
taken over some data reading then we must delay initial
read-in of other data.

Fixes: #13288
Signed-off-by: Donald Sharp <sharpd@nvidia.com>