Defining initial API for field sets (#633)
Defining initial API for field sets (#633)

* Defining API for field sets

* Adding orderBy

* Adding DESC comment

* Adding comments

all-of-us/workbench,all-of-us/workbench,all-of-us/workbench,all-of-us/workbench,all-of-us/workbench,all-of-us/workbench,all-of-us/workbench,all-of-us/workbench,all-of-us/workbench