Check consistency of data and simulations

[yannikschaelte]

Feature description
In most cases, the set of summary statistics and their dimensions should coincide between all simulations and the observed data. Thus, add a check somewhere (Model class?) for consistency, allowing for an optional override if that is not desirable (non-default), e.g. if simulation dimensions can vary.

Motivation/Application
E.g. numpy is quite generous due to broadcasting, which may hide errors.