bgpd: Show neighbor advertised paths including addpath

bgpd: Show neighbor advertised paths including addpath

Without the patch only the best path is displayed.

With the patch, display all paths including addpaths, but only for non-JSON
output to avoid breaking existing output.

E.g.:

```
munet> r2 shi vtysh -c 'sh ip bgp nei 192.168.2.3 advertised-routes'
     Network          Next Hop            Metric LocPrf Weight Path
 *>  172.16.16.254/32 192.168.2.3              0             0 65003 ?
 *   172.16.16.254/32 192.168.2.4              0             0 65004 ?
 *>  192.168.2.0/24   192.168.2.3              0             0 65003 ?
 *   192.168.2.0/24   192.168.2.4              0             0 65004 ?
```

Before it was:

```
munet> r2 shi vtysh -c 'sh ip bgp nei 192.168.2.3 advertised-routes'
     Network          Next Hop            Metric LocPrf Weight Path
 *>  172.16.16.254/32 192.168.2.3              0             0 65003 ?
 *>  192.168.2.0/24   192.168.2.3              0             0 65003 ?
```

Signed-off-by: Donatas Abraitis <donatas@opensourcerouting.org>