laser init: file vs func

[k-wolfinger]

When we initialize a laser from function and another from file, with the same parameters, we are getting different values for the total number of photons in the laser.

We should get something similar. Right now, for 1uJ pulse we get 1.6e10 (function) vs 4.0e12 (file)

I assume the intensity plots look different as well. (I'll check this)

[k-wolfinger]

Found the issue:

• When initializing from function (and file), we want the input pulseE to equal the total calculated energy in the wavefronts
• There is a constant_factor included in the function init to make sure this is the case
• When we changed the calculation of intensity (from srw provided intensity to srw provided fields + our intensity calculation) we didn't change this factor

Now both file and function init (with the same laser params) give the same number of photons and same total energy