zebra: Push all configured IP addresses when the interface comes up

zebra: Push all configured IP addresses when the interface comes up

Let's say we this:

```
$ ip link set down dev r1-eth0
$ ip link set up dev r1-eth0
```

But at the same time we have this interface configured by the FRR too:

```
interface r1-eth0
 ipv6 address fe80:1::1/64
exit
```

We never re-add fe80:1::1/64, when the interface comes up, and we have a
strange situation where NHT stops working and other stuff depending on NHT
stops too (BGP peering, etc.).

Closes: https://github.com/FRRouting/frr/issues/15050
Signed-off-by: Donatas Abraitis <donatas@opensourcerouting.org>