add "display" name to updaters

[hdonnay]

trafficstars

Since API users are surfacing updater names to humans (see quay/quay#937), we should consider adding a nicer looking name to updaters for this purpose.

The current updater name is just a system-unique string used as an ID for various updater processes. We could also develop a heuristic to generate a nicer looking name for progressive enhancement.