Enable DataStore search from R

[RobLBaker]

Write a function that allows a user to query DataStore directly from R (take advantage of existing DS search tools via API calls).

This will allow the user to pipe the query into the get_data_package and load_data_package functions and ideally facilitate metadata analyses.

[RobLBaker]

Good use case for this, but may be best to wait until the DataStore API gets refactored.

[wright13]

Likely want to make a separate package to act as an API wrapper. Eventually.