fix(transform): use `time` attribute instead of `index_map['time']`
fix(transform): use `time` attribute instead of `index_map['time']`

`CollateProducts` now creates the time axis of the output `TimeStream`
container from the `time` property of the input container, so that
the time axis is defined with respect to the integration centre
instead of the integration start.

radiocosmology/draco,radiocosmology/draco