Convert actions to tk-multi-loader2 schema

[Ahuge]

Changing references of sg_data to sg_publish_data

This change is discussed on the community forum topic "Tk-multi-shotgunpanel & tk-multi-loader2 using same actions code?"

The gist of it is that I am aware this would require a breaking api change, however the two actions generation code only have the change of the method parameter names.
This synchronizes them and no longer requires small hacks like the ones suggested in the forum topic.

[Ahuge]

I know there are rough usage metrics on which is used more, shotgunpanel or loader2, I assumed that loader2 is used more but if I am incorrect, it may be easier to break api compat of loader2 and conform it to shotgunpanel.

Let me know if you'd prefer me to submit the inverse change on loader2 instead of here!

[Ahuge]

Error is with azure build system