tools: frr-reload fixes for deleting vrf static routes

tools: frr-reload fixes for deleting vrf static routes

Problems reported that in certain cases, frr-reload.py would
delete vrf static routes inadvertantly due to two different
reasons. First, vrf statics with null0 or Null0 nexthops would
fail the match since rendered as blackholes.  This was already
fixed for non-vrf statics so added for vrf-based.  Second,
frr-reload would fail to match due to different formats for
adding the command. If entered in the old way
"ip route x.x.x.x/x y.y.y.y vrf NAME" and rendered
in the new sway "vrf NAME\nip route x.x.x.x/x y.y.y.y" it would
fail to match do an inadvertant delete.

Ticket: 2570270
Signed-off-by: Don Slice <dslice@nvidia.com>