CoolTupleReader logic rework.

[hugy718]

Reasons:

• change in cohort storage format. global id list > string list
• global id no longer unique across cublet
• previous impl assumes that users with unique id and the order in cohort file and raw data are the same.

plan

map string to global id at the beginning for each cublet.
iterate through data and check if user is contained in the target cohort list for the cublet

status

comment out CoolTupleReader for now. The downstream exploration application is already commented