Modify database ORM code to use UUIDs

[bryankennedy]

When we save run records to the database, we are currently using sequential integer IDs. This is nice because it's simple and easy for humans to read. However, as we're implementing data syncing between multiple databases in multiple locations, we're going to run into collision problems. Run ID #13 at COSI can't sync up with SMM because we might have our own run #13.

UUIDs are a nice solution for this. Although they are somewhat harder for humans to read, each record, no matter where it is generated, always generates a unique ID. This will make it easy to merge the various databases together into a single central record of all the xMacroscope data.

[bryankennedy]

I've been working on this in a separate branch since I don't know how this change will affect the MAV display's GQL queries. We don't need this functionality right when we install at COSI, since it's technically the only install. We can just replicate the COSI data up to the cloud and not worry about any collisions. But I'd like to get this setup before generating too much data. Once we go live, we'll need to massage the data afterwards to backport this work.

If MAV impacts are minimal, it's possible we can get this working before the COSI install.

[bryankennedy]

@brandonwkipp can you merge the UUID work into the develop branch once your related work here is ready?