Merge pull request #15723 from opensourcerouting/feature/extended_link_bw_refactored_v1

bgpd: Implement extended link-bandwidth

diff --cc bgpd/bgp_route.c
Simple merge

diff --cc bgpd/bgp_vty.c
Simple merge

diff --cc bgpd/bgpd.c
Simple merge

diff --cc doc/user/bgp.rst
Simple merge