Maintains a timestamp of when each profile was last active on the server.
Timestamp is refreshed on two events: `game/start and `game/keepalive`
Timestamp is used to determine if a profiles hideout should be processed. If a profile has a timestamp older than 90 minutes, it is not processed. (could be set lower but its a conservative value)
This has the side effects of not adjusting the `sptUpdateLastRunTimestamp` property, resulting in `saveProfile()` not running for every profile.
My testing shows a 20x perf increase for every profile in SPT not in use.
Service could likely be used in other scenarios to avoid doing unnecessary work
