[enhancement] Enable `Packet.show()` and `show2()` to output lines to `logging`

[alxroyer-thales]

Instead of the standard output by default (print() called in Packet._show_or_dump()).

It would be useful when integrating in a project that makes intensive use of logging.

[alxroyer-thales]

Suggestion:
It could be done by extending the type of the dump parameter from bool to an union with Callable[[str], None].
When dump is a callable, then it would be called.
Otherwise, the current behaviour would be followed.

[alxroyer-thales]

If ok with the suggestion above, I may provide a PR for that.

[gpotter2]

I'd say that this is too niche to be in Scapy. One can do

>>> import logging
>>> pkt = IP()
>>> logging.warning(pkt.show(dump=True))
WARNING:root:###[ IP ]###
  version   = 4
  ihl       = None
  tos       = 0x0
  len       = None
  id        = 1
  flags     =
  frag      = 0
  ttl       = 64
  proto     = hopopt
  chksum    = None
  src       = 127.0.0.1
  dst       = 127.0.0.1
  \options   \