Remove false positives in Jacobian sparsity

I looked into matrix colouring for Jacobian computation with ForwardDiff.jl (https://youtu.be/bY2VCoxMuo8?si=RzYQz9m_dq7gRG5k) from which it became clear that Jacobian sparsity is very important for performance. The latest adjustments to sparsity.jl in https://github.com/Deltares/Ribasim/pull/1349 removed complexity but added false positives. I propose removing the false positives again with a generic approach:

[x] Define

abstract type AbstractConnectorNode <: AbstractParamererNode end

and make all connector node structs of this abstract type.

[x] When constructing the Jacobian prototype, apply a generic method

function update_jac_prototype!(
    jac_prototype::SparseMatrixCSC{Float64, Int64},
    node::AbstractConnectorNode,
    graph::MetaGraph,
)::Nothing
    ...
end

for all connector nodes. It is assumed that the flow over a connector node always depends on the upstream basin. Whether this flow depends on the downstream basin can (probably) be deduced from whether fractional flow is allowed downstream of the node type.

[x] Make a special case in this generic method for downstream basins which are connected via fractional flow.
[x] Make/keep a separate method for PidControl.

Deltares / Ribasim

Remove false positives in Jacobian sparsity #1575