create and update a workflow using a single endpoint

[laureD19]

based on discussions started over the summer 2024, we agreed on simplifying the creation and update of Marketplace workflows content type.

The idea would be to create and update a workflow using a single endpoint, with similar information than when you get a workflow. The order of steps would matter, and steps would keep their persistent IDs.

The behaviour for POST and PUT for workflows would send a list of steps as a list of arrays where some steps would have IDs and some would not.

(From the front-end, this will mean that users will not get the possibility of reusing the steps).

@tparkola - more detailed specifications should be described for initial discussion in the following gdoc: https://docs.google.com/document/d/1F1jsI92B1M05r3aoNWIOXbV_r1GwqfnCtWtpWnjOUAs/edit?usp=sharing