bgpd: Remove hidden `neighbor X route-map Y <in|out>` command

bgpd: Remove hidden `neighbor X route-map Y <in|out>` command

This command was put in place to allow upgrades for the
neighbor command from the BGP_NODE and have it put
into the ipv4 uni node instead.  Since this
utterly kills the yang conversion.  I believe we need
to remove this.  Since people upgrading will just loose
the route-map applicatoin( if they are using such an old
config ) and RFC 8212 will come into play.  They'll figure
it out pretty fast.

Fixes: #7983
Signed-off-by: Donald Sharp <sharpd@nvidia.com>