_classify_arg updates for google flights presentation as of 8/16/24

[Kumaezenjae]

in flight.py, the _classify_arg() function may benefit from these changes or similar ones:

• CO2 condition
  Change endswith to in, some entries have CO2e
  elif 'CO2' in arg and self._co2 is None:
• Emissions condition
  Change endswith to in and handle or omit case sensitivity on E
  elif 'missions' in arg and self._emissions is None:
• Stops condition
  Add possibility of minutes without hours in stop time
  elif (('hr' in arg or 'min' in arg) and arg[-3:].isupper()) or (len(arg.split(', ')) > 1 and arg.isupper()):
  Add additional stop condition which catches layovers reported as an airport without a duration
  elif len(arg) == 3 and arg.isupper() and not self._origin is None and not self._dest is None:
self._stops = arg
• Airlines condition
  Adjust criteria to catch and omit a few more different cases that were appearing in results
  elif len(arg) > 3 and arg != 'Separate tickets booked together' and arg != 'Change of airport' and not 'hr' in arg and not 'min' in arg:

in flight.py, the _parse_args() function may benefit from this change and similar ones:

• Airline Placeholder
  After parsing, put in a placeholder for missing airline
  if self._airline is None or self._airline == "" or len(self._airline) < 2:
self._airline = "--"