make aggregates timeout configurable

[KalmanMeth]

In order to make the aggregates timeout configurable, we need to add a field in the config file, and we probably need to introduce a breaking-change to add a rules section in which to put all the aggregation rules. Currently the rules are placed directly at the highest level in the exract: aggregates: section.

[KalmanMeth]

Perhaps allow a timeout field in each of the individual rules. In that case, we need not (yet) create a rules section.

[KalmanMeth]

Current default timeout is 10 minutes, which we should also re-consider.