Improve the syntax for spraying from a k8s landingzone

To spray from a k8s landingzone you currently have to use a fake srcip of 127.0.0.1 and add an extra parameter nolocal=true.  E.g.

dfuplus action=spray nolocal=true srcip=127.0.0.1 srcfile=/mnt/c/hpcc-data/dropzone/originalperson dstname=tut::originalperson dstcluster=data recordsize=124 server= 10.109.12.125:8010

While this works, it is not user friendly.  Instead there should be an option to specify a source plane, and allow the srcfile to be a relative filename.  E.g.

dfuplus action=spray srcplane=mydropzone srcfile=originalperson dstname=tut::originalperson dstcluster=data recordsize=124 server= 10.109.12.125:8010

This would be useful for both bare-metal and k8s systems.  It would require changes to the esp service (and ideally the fileservices functions as well.)

This may be a duplicate - if so please link.