Add function to waterdata module for submitting custom CQL2 to water data APIs

[ehinman]

dataRetrieval has a function for a user to submit CQL syntax to make more customized calls to the API endpoints (ex. using conjunctions like IN, AND, OR, BETWEEN, NOT etc). This would be a helpful function to have in drpy too.

See dataRetrieval function: https://github.com/DOI-USGS/dataRetrieval/blob/main/R/read_waterdata.R

And CQL2 documentation: https://api.waterdata.usgs.gov/docs/ogcapi/complex-queries/