Read wavelength and flag 'isLaserEnvelope' from lasy file

[IlianCS]

Next implementations for lasy files reading, following #3910

Files that need to be changed:

LaserProfiles.H
LaserProfileFromFile.cpp
LaserProfileGaussian.cpp
LaserProfileFieldFunction.cpp
LaserParticleContainer.cpp

Originally we wanted to read the wavelength, polarization and e_max from the lasy file. We also wanted to read the full field if isLaserEnvelope is set to False in the file.

Update: We are not looking for reading the polarization and e_max in the file anymore.
e_max: we are waiting for e_max to be stored inside the lasy file because we don't want to loop over the whole file in WarpX in order to compute it.
polarization: complex meta data set by the user when creating a lasy file to define, for instance, circular and elliptical lasers. As WarpX is not able to read complex polarization, we cannot read this attribute so we let it as a choice for the user to provide a linear polarization in the inputs file.
isLaserEnvelope: we want to read the boolean inside the lasy file but lasy does not have the capability yet to store the amplitude instead of the envelope.

TODO list (updated):

• Read wavelength from file.
• Read the flag isLaserEnvelope.

[ax3l]

cc @MaxThevenet @RemiLehe I think this might need an addition of a few attributes in the openPMD laser envelope extension? Did we already start discussing this, sounds like a good idea :)

https://github.com/openPMD/openPMD-standard/blob/upcoming-2.0.0/EXT_LaserEnvelope.md