Rename "task" to "job" and "pipeline" to "task"

[JeanMertz]

After using and talking about Automaat for a while now, I think the naming scheme is confusing – especially for non-technical people – and thus should be changed.

Specifically, right now a pipeline is a collection of steps that you can run, and when you run a pipeline, it creates a task based on the configuration of that pipeline.

Technically, the name pipeline makes sense, since you are chaining together a set of steps which each run a single processor with some configuration attached. But, when talking about it within the UI, in the abstract, without (having to) knowing how a pipeline works, this analogy breaks down.

Instead, talking about a task makes things much more clear, as the dictionary defines a task as "a piece of work to be done or undertaken.", which fits perfectly in this context.

Similarly, whereas tasks currently mean "a pipeline that is actively running", it makes more sense to call this a job: "the object or material on which work is being done ".

So, in conclusion: the term pipeline will disappear, the term task will take the role of a pipeline, and the term job will take the role of a task.

This work was already done for the web client in 2d9bc81, so this issue is to track the change of the terms in the rest of the code base (mostly the API server).