Split from #8633 (#8633 (comment))

The Exchange Online Message Trace integration currently ties Polling Interval to both Polling and Lookback. The issue here is that these events are eventually consistent, meaning that some data can be missed on first lookup.

It should be possible to define the Poll Interval and Lookback interval as two different settings so that the lookback interval can be set longer than the poll interval.

### Tasks
- [ ] Look into adding separate configurable lookback intervals (separate from the initial_interval lookback), that work along side with the standard polling interval.

Edit: For reference here is the official document which mentions that events can "lag" by up to 24 hours. This may however, be mitigated by the StartDate and EndDate fields (per their descriptions)