Automatically recognize if a model is best run with daeMode

[casella]

Power systems models built with the PowerGrids library have a peculiar property: while the Jacobian of the DAE system is highly sparse, if the system is causalized, the ODE formulation has a dense Jacobian, which makes using implicit ODE integration extremely less efficient than direct DAE integration.

This is a structural property that is easily recognisable by looking at the sparsity ratio of the DAE and of the ODE Jacobians. If the former is much lower than the latter, we should issue a warning and propose the end user to use --daeMode for more efficient integration.

In OMEdit, it should be possible in this case to set the flag in an annotation by just clicking on some button.

We should probably do the same for models that have very large nonlinear strong components, because in that case there is a nested iteration of large nonlinear implicit solvers (the inner algebraic solver, and the outer BDF solver) that will be much less efficient than solving both at once with the BDF solver. Dymola has been giving this warning for a while.