Adds 2 optional parameters to BGPSpeaker evpn_prefix_add:
tunnel_endpoint_ip: To allow for VTEP IPs other than the implicit local router ID
mac_mobility: To insert an extended community with a sequence number for managing MAC Mobility (using existing BGPEvpnMacMobilityExtendedCommunity class)
Adds 2 optional parameters to BGPSpeaker evpn_prefix_add: