Make auditing compatible with different sub-protocols about glados

[pipermerriam]

I think it may make sense to simplify our schema as follows.

table Content:
    id: i32 database primary key
    protocol_id: <sub protocol id>
    content_key: <full content key>
    content_id: <32 byte content_id>
    first_available_at: <datetime>

we would want a multi column unique clause for (protocol_id, content_key, content_id)

This combines the existing ContentID and ContentKey tables into a single unified table and I think it satisfies all of our needs and makes our database a lot simpler.

I'm fine with the quick way of getting here, which would be to destroy the existing tables and create new tables and ignore doing any data migration.

[perama-v]

I'm fine with the quick way of getting here, which would be to destroy the existing tables and create new tables and ignore doing any data migration.

Say no more! 👟 👟

I interpreted first_available_at as: "first available to glados-audit", as in time that the item was added to glados-db.
So if we add to glados-db via backfilling, old chain data will have a recent timestamp for first_available_at.