elegant (feature request): import beam properties to Sirepo/SRW

[bruhwiler]

This is a request from an elegant user:

"Is there a way to import data from elegant into SRW? E.g., it would be nice to be able to use data from the twiss_output and moments_output commands to define the beam properties, or even the output of particle tracking."

https://www3.aps.anl.gov/forums/elegant/posting.php?mode=reply&f=17&t=937