Defined start/stop time for logging

[davidsanner]

As per forum request: https://www.traccar.org/forums/topic/time-delay-service-status-on-probably-an-enhancement-request/page/2/#post-26434

Feature add: ability to control start/stop time (or a simple count down timer) for when traccar starts sending data (& requesting GPS location). Traccar client would still be started manually but could be in an 'idle' mode until timer counts down or start time is reached.

This would save on battery & a bit of data... also decrease the likelihood of forgetting to start the App when one delays it use until needed.