Change wake function in CircularResistiveWall to enforce fundamental theorem of beam loading.
Rework Resonator class to set manually time and frequency arrays and enforce fundamental theorem of beam loading.
Change to WakeField.impedance_components and WakeField.wake_components to allow methods begining by W or Z in WakeField subclasses.

Add transverse wake potential to WakePotential and move class to dedicated file
Merge Resonator and TransverseResonator into Resonator with dedicated file
wakefunction_from_imp -> change trimming to allow for a float value
wakefunction_from_imp -> transverse impedance divided by 1j, to be checked with impedance convention but ok with benchmark
Wakefield -> add wake_components