Spike: examine previous/legacy decisions pulled into the new QX FluxBuilder.

We have been dev'ing fast on the new QX FluxBuilder (new DataExplorer), but this meant bringing in certain decisions previously made from Notebooks code. This ticket is a tracker of some of the decisions/code brought in, such that we can re-assess at a later date.

## TimeRanges:
* in the rest of the UI application, we make use of the explicit `TimeRange` type --> then converted to the UI `Variable` type.
* notebooks had a previous decisions:
* to avoid the `Variable` type.
* to convert the `TimeRange` type, to string objects with any types.
* then does lots of spreading of objects with any types, to override. And override the original override. Etc.
* code:
* legacy code used in the shared QueryContext
* introduced code (copy/pasta) in the new ResultsPane

## Variable injection into code:
* in the rest of the UI application, variables are provided as extern definitions.
* notebooks does an AST-modification (then stringification) to insert variables directly into the user's flux query
* code:
* legacy code used in the shared QueryContext

## WindowPeriod calculation:
* the rest of the UI application uses common helper functions for the windowPeriod calculation:
* these helpers are currently being fixed (PR in progress)
* wrong calc: https://github.com/influxdata/ui/issues/4646
* notebooks uses it's own copy/pasta of the old/incorrect calculation.
* therefore, notebooks is not getting a fixed calculation. Will still be wrong.
* code:
* legacy code used in the shared QueryContext. (uses notebook's windowVariable calculation.)

## Additional potential improvements found in the shared QueryContext and ResultsPane:
* https://github.com/influxdata/ui/pull/4652#discussion_r880157474
* https://github.com/influxdata/ui/pull/4652#discussion_r880160373
* https://github.com/influxdata/ui/pull/4652#discussion_r880148190
* https://github.com/influxdata/ui/pull/4652#discussion_r880171630