ordered pipeline exec

[dselans]

Changed to do ordered pipeline exec. Needed so that schema inference is always executed first - that way last step status can be put in resp. Without this, it is possible that schema inference pipeline gets executed first and so would cause the incorrect status set on the response.

Given that a lot of changes need to occur on the server - maybe there's a better way to do this.

Need to discuss with @blinktag

[dselans]

COPY/PASTE:

Arrived at the conclusion that we need to establish pipeline order on server. Without that, we will never be able to 100% say that X should execute before Y - at best, they are "it will probably happen".

Closing this PR in favor of the "pipeline refactor" PR.