2021-08-20: rewritten for CMK 2.0 by thl-cmk[at]outlook[dot]com
            based on the "BGP Peer State Check" check by Thomas Wollner (tw[at]ollner-net[dot]de),
            (http://wollner-net.de/check_mk/network_checks/bgp_peer-1.4.mkp)
2021-08-21: added more perfdata, added metrics file
2021-08-22: added WATO options, streamlined with cisco_bgp_peer
2021-08-29: moved static (longoutput) to inventory plugin
            moved helper functions to utils/bgp_peer
            WATO: removed htmloutput and infotext_values option
2021-11-14: merged check function with cisco_bgp_peer
            moved parse function to utils/bgp_peer
2022-04-02: WATO: added bgp neighbour states
            rewritten bgp neighbor state handling (made configurable)
2022-04-17: added peer_unavail_reason/peer_unavail_reason_str for huawei bgp peers