[FEATURE] Create and provision workflow in the same time

[amitgalitz]

Is your feature request related to a problem?

Currently in order to provision a workflow, you first have to create the workflow and receive a workflowId.

/_plugins/_flow_framework/workflow
{}
response:
workflowId: "G513W4wBRItvelfmy_w4"
/_plugins/_flow_framework/workflow/G513W4wBRItvelfmy_w4/_provision
response:
workflowId: "G513W4wBRItvelfmy_w4"

What solution would you like?

We should have the option to add an optional provision=true flag to the create API to start provisioning right after create:

/_plugins/_flow_framework/workflow?provision=true

[dbwiddis]

This duplicates #259

[amitgalitz]

This duplicates #259

didn't notice we had this already, closing this one