Implement Cross-Polarization Antenna Factors - Now clean

[AlanSalcedo]

This pull request updates the cross-polarization treatment in the antenna factor calculations.

Key Changes:

• Co-pol and cross-pol gains, effective heights, and phases are included in the antenna response.
• For Rx, co-pol and cross-pol contributions are added coherently in voltage.
• For Tx, co-pol and cross-pol are treated as orthogonal emitted field components, with: h_Tx=\sqrt{(h_co^2+h_cross)^2}.
• Assuming similar co-pol and cross-pol Tx phases, the co-pol phase is used as the common Tx phase, while the co-/cross-pol amplitude ratio determines the emitted polarization direction.
• The Tx amplitude is applied following: E(f) ~ 2i* f/c * Z_0/Z_L * h_Tx(f)* V_src(f),

Usage:

Add CROSSPOL_RX=1 and/or CROSSPOL_TX=1 to the setup file. Both remain 0 by default to reproduce the nominal behavior. CROSSPOL_TX=1 is relevant for simulations that explicitly model a transmitting antenna, such as EVENT_TYPE=12.