Return result objects from tasks to get better visibility

[batpad]

If we return an object with some data from the tasks, we can then see TaskResults in the admin for some users. We should do that to improve visibility of tasks and make it easier to debug.

For now, my thoughts:

• Enable TaskResult in the admin to see run tasks (we can worry about disabling it for general users later if its confusing)
• Ensure we return a result object from tasks, similar to https://github.com/developmentseed/moz-proenergia-backend/blob/main/proenergia/celery_tasks.py#L26

We should return the result for errors and success with appropriate messages and status. This will then automatically populate the TaskResult model and allow us to see executed tasks and errors, if any, in a slightly nicer manner than having to go through server logs.

@willemarcel does this sound fine to you?

[willemarcel]

@batpad On c1c26ed I started to save the error message in the VectorFile and ScenarioFile model when the task fails. Do you think it is good enough? My intention was to give the user some information about it, so they can see it easily in the admin. The ogr2ogr/tippecanoe error message won't be always easy to understand, but I think it can help.