Collapse OrderDurationRecorder and WaitingTimeTracker

[iamgabrielma]

Related: #15082 (comment)

We have 2 different components that do similar work, these track the duration of an action from start to end, then this is used to send an event to Tracks. Would be worth checking if both are needed, and perhaps collapse functionality into a single component.

If that's not the case and we need to keep both, then there's some improvements that could be done to WaitingTimeTracker:

timeIntervalSince1970 feels like quite an implementation detail, as the timestamp can be based on different reference dates. As a further improvement, could this function just return a Date instead of a time interval? Then the time interval calculation could be internal to the time tracker

another future improvement would be to have an explicit start function in addition to end, so that the time tracker can be initialized first without starting time recording.

[dangermattic]

🚫 Please add a type label (e.g. type: enhancement) and a feature label (e.g. feature: stats) to this issue.