git: parse Git Protocol version from pkt-lines
In Git's packfile transfer protocol, the initial server response contains the version of the Git Protocol in use; version 1 or version 2 .
Parse out this information following up on work started in MR !805 (closed)  by Izabela Bakollari and advice provided by Ronnie Sahlberg, add it as a field for ease of reading and filtering.
 !805 (closed)
Related to #17093