epan: Add support for EPMD_ALIVE2_X_RESP in EPMD dissector

The EPMD dissector in Wireshark did not recognize EPMD_ALIVE2_X_RESP messages (type 'v', code 118) generated by the official Erlang/OTP EPMD server when highvsn >= 6. These messages were displayed as uninterpreted data instead of being properly decoded as EPMD protocol.