Add Beam "energymin" and "energymax" to main output

[ChristopherMayes]

It is useful to see the minimum and maximum particle energy in the main output. Could we add:

• Beam/energymin: minimum particle energy in a slice
• Beam/energymax: maximum particle energy in a slice Similarly, it would be useful to have the same for x, px, y, and py.

Describe alternatives you've considered The only alternative is to dump particles on regular intervals and inspect them, which is slow.

[svenreiche]

I will add them soon since it is rather easy to implement.

[svenreiche]

Minimum and maximum value for x,px,y,py and energy have been added to the output. For large files this output can be suppresed with enable_aux_output = False in the main setup deck. The addition is in the current dev branch but will be transferred to the master branch with a new release.