AD: BEM: Adding quasi-steady outputs Cx, Cy, phi

[ebranlard]

This pull request is ready to be merged

Feature or improvement description
This pull request stores the quasi-steady flow angle phi, together with the projected coefficients Cx and Cy used by BEM, and therefore adds BEM_Cx_qs, BEM_Cy_qs and ,BEM_phi_qs to the AeroDyn Nodes outputs.

The current output channel Phi is different from BEM_phi_qs because, BEM_phi_qs, the flow angle from the BEM constraint equation, gets overwritten by one that is consistent with Vx, Vy, a, and a' (stored in Phi). This erasing of the flow angle makes debugging BEM harder.

The following were added to the Xlsx outlist parameters file:

• BEM_Cx_qs : Rotor normal coefficient "cn" used in quasi-steady BEM algorithm, projected from Cl, Cd, Cm. In Polar BEM, this is Cxl
• BEM_Cy_qs : Rotor normal coefficient "ct" used in quasi-steady BEM algorithm, projected from Cl, Cd, Cm. In Polar BEM, this is -Cyl
• BEM_phi_qs: Flow angle used in quasi-steady BEM algorithm (from constraint equation), different from the Phi output (based on Vx, Vy and inductions factors)

Impacted areas of the software
AeroDyn BEMT

Additional context
The "erasing" of the flow angle output occurs in BEMT_CalcOutput:

1. BEMT_CalcOutput_Inductions is called, which leads to the constrained phi value.
2. When calling SetInputs_for_UA_AllNodes , the function ComputePhiWithInduction is called, which leads to a different phi:

 phi(i,j) = ComputePhiWithInduction( u%Vx(i,j), u%Vy(i,j),  axInduction(i,j), tanInduction(i,j), u%cantAngle(i,j), u%xVelCorr(i,j) )