App should generate and save a unique user ID for intercom

[mcous]

overview

As an app user, I would like my Intercom conversation history to be preserved through app launches.

current behavior

If the user closes the app, their intercom conversations and history are lost.

implementation details

Similarly to how we generate a unique app_id for analytics purposes, we should generate another unique ID for use as the user ID. This ID should be different than the analytics ID so we cannot link specific users to specific analytics events.

[pantslakz]

@mcous I should note that this is happening even if user just closes app and restarts it - they lose their prior convo.

[mcous]

@pantslakz did not realize that was the case. Updated ticket and will prioritize higher, accordingly