Allow to specify recommended user settings via task type

[daniel-wer]

See https://discuss.webknossos.org/t/settings-via-task-type/1173

[philippotto]

I think the easiest way would be to allow the task type creator to add some settings JSON which is then persisted and upon task start we can show a message "the following settings are recommended for this task. do you want to apply these?". The only problem with this approach is that we would need to expose our internal settings JSON format.

Another possibility would be to add the settings UI to the task type dialog. Then we would encapsulate the json setting names away. What do you think @daniel-wer ?

[fm3]

@philippotto @daniel-wer do you already have plans for this? What do you need from the backend? :)

[philippotto]

I think we would only need a route to put and get some json object on a task type (e.g., a preferredSettings attribute). I'll double-check with heiko whether this should be per task type or for each task.

/edit: He actually wrote "per task type".

[fm3]

backend part should be done through #3415 :)