no longer assume that prob.p is the correct parameters for a problem lacking callbacks and DAEs

[isaacsas]

Per the discussion in SciML/ModelingToolkit.jl#2733 parameters may not always get updated for non-DAE models anymore until integrator initialization. We should therefore no longer assume prob.p are updated and correct parameters associated with the prob. I think this is a potential issue in some of the extensions that needs to be checked and updated.

[isaacsas]

This probably impacts tests in a number of places too.

[ChrisRackauckas]

Just to be clear, "no longer" - this change happened in 2017. It is for example a very essential feature in Pumas that parameters are updated in the callback initialization, which can do all sorts of things like add tstops the user may have forgotten https://github.com/SciML/DiffEqCallbacks.jl/blob/master/src/iterative_and_periodic.jl#L163-L169, project the initial state (and all subsequent states) onto a manifold https://github.com/SciML/DiffEqCallbacks.jl/blob/master/src/manifold.jl#L118-L139, etc. So it could not necessarily be assumed even before Catalyst was created.