Feat/optimizely webx visitorid

[patrick-wu]

Summary

This PR does the following:

• Checks for particular prefixed attributes passed down by Rokt manager, and formats them to condensed attributes
• Also sets rokt.clientcustomerid to be the same user ID passed down from RoktManager / the Optimizely SDK

Testing Plan

{explain how this has been tested, and what additional testing should be done}