Adds to Aggregate Candidate Metric query and count

Also, designs setup for authentication entry collection, and creates a
new abstraction object for said collection. Given that authentication
entries can occur in loops, this starts to think about how we might
aggregate authentication entries.

On top of this, this re-designs the session id in the collection system
so that it is immutable once created.

Bug: 271135048
Test: Build + Won't submit w/o E2E test

Change-Id: Ib32036430f5cf0249a651a2867758de08f19e63b