Make walk deterministic so multiple screens will have similar content

[cartland]

The logic is run independently on each surface and we want to avoid communication, but it would be nice if the walks looked similar to each other (but still random).

Idea: Seed the waypoints for a person based on the timestamp of the NFC update. You should be able to generate enough waypoints after receiving the NFC timestamp update so that they stay synchronized for a long time (6 hours? forever?). The people will start out in random locations that are different, but as each person uses their wand, the maps will start to converge on similar behavior.

The NFC update contains a timestamp in the root of the document.

nfcData
- nfcLogicalId: "cartland"
- nfcReaderLocation: "hallway"
- nfcUri: "https://marauder-129.web.app/?logicalid=cartland"
timestamp: October 22, 2019 at 1:41:20 AM UTC-7

[cartland]

The random number generation is deterministic, but the code paths are not. Some parts appear consistent. For example, when a wand is tapped that individual path appears to act consistently on different devices. However, after a while, things seem to get out of sync.