Allow initialisation of p_inj and q_inj in SP_NetworkInjection

[martinmoraga]

Currently, it is not possible to initialise the active and reactive power of the NetworkInjection class for powerflow simulations.

This could be solved by adding the line:

sol_Q(pv->matrixNodeIndex()) += extnet->attributeTyped<CPS::Real>("q_inj")->get() / mBaseApparentPower;

in

dpsim/dpsim/src/PFSolverPowerPolar.cpp

Line 93 in ffc5080

} else if (std::shared_ptr<CPS::SP::Ph1::NetworkInjection> extnet =