Rewrite `ext.tasks`

[Paillat-dev]

Similar to #56, make sure that ext.tasks does not rely on any code being part of the main library. This may need to remove or modify some of its features in a breaking, way, possibly the create_loop param.

ext.tasks is removed in #217

[Lumabots]

i could do this, i used loop a lot and could enjoy to rework it as well