Fix return values of quick add meta structure

[lefcha]

Fixes Meta model to allow None values in project, section, and assignee tuple fields, matching the actual quick add API response.

[goncalossilva]

👍

How can this happen?

[lefcha]

@goncalossilva What do you mean?

For starters, in the backend code in the return values we might return None.

Then IIRC, the project is populated if the #<project> has been specified and it could be found, otherwise it's empty and it's assumed that the task in the Inbox. The same holds for section and assignee.

Now if you're wondering why we need this now, I think it's related to some update that took place in dataclass-wizard in 0.39.0 relating to how None values are handled, but I didn't investigate further. The fact that the backend can return these values was enough.