extra arguments db_get_sites

[swploum]

db_get_sites only shows samplingfeatures that are assigned as sites. For example waterquality stations and streamgages are not shown. An extra argument would be usefull where you can specify which samplingfeature type you want to see.

For example:
db_get_sites(db, CVtype='all') as default

but you can specify by writing:
db_get_sites(db, CVtype='waterQualityStation')

[swploum]

In the case this is incorporated, a get_cv_terms example could provide the option to see which samplingfeature CV's are in the db