ENH: Incorporate metadata from Models when pysat capable

[rstoneback]

Is your feature request related to a problem? Please describe.
Some of the functions in extract don't take in a pysat.Instrument object for all inputs. This results in some situations where Model metadata that could be incorporated isn't, since there isn't any provided.

Describe the solution you'd like
When the functions are upgraded to work better with pysat, ensure that metadata is also incorporated.

Describe alternatives you've considered
Ignore metadata

Additional context
Getting better, slowly but surely.