[client] Add CRUD operations for Tasks, TaskTypes, Projects etc.

[normanrz]

It should be possible to create, read, edit and delete tasks and their adjacent types from the Python library. It would also be great to have downloads of the annotations of projects etc.

[fm3]

https://github.com/scalableminds/webknossos-libs/pull/574 implements a first iteration for Task Management. Remaining follow-Up ideas:

• [x] Task.create method (not from files, but list of parameters)
• [ ] Project.create
• [ ] Delete + Update methods

[fm3]

Removing my assignment for this sprint as #574 is now merged and implements the part of this issue we prioritized for the moment