Use queue for car commands

[pkuehnel]

To increase adjustment frequency while letting all adjustments, especially via BLE, more time to process (timeout of 21 seconds should also be removed) use a queue of commands for each car. The object might contain the following properties:

Command //e.g. wakeup, change amp,...
InQueueSince
State //e.g. waiting, executing, finished, cancelled
Task //The actual task to execute
CancellationToken //to trigger task cancellation from external