fix: Add duration to getTask, addTask, quickAddTask and UpdateTask

[thales-fukuda]

Closes #241

[henningmu]

@thales-fukuda thanks a lot for getting this done, it works perfectly 🎊

@pawelgrimm has a little bit more context on the duration feature, so I'd like his opinion before releasing this:

• The API only accepts durations when a due date is set; otherwise, it silently discards the durations
• The app is only displaying durations for tasks with due time and durations < 24h

Should we mimic these conditions in the SDK as well, or allow everything the API allows?

[pawelgrimm]

Thanks for the PR, @thales-fukuda! I left some small comments for you — let me know if you'd prefer I apply the proposed changes myself.

@pawelgrimm has a little bit more context on the duration feature, so I'd like his opinion before releasing this:

• The API only accepts durations when a due date is set; otherwise, it silently discards the durations
• The app is only displaying durations for tasks with due time and durations < 24h

Should we mimic these conditions in the SDK as well, or allow everything the API allows?

Let's keep the SDK aligned with the API — the only requirements are that both (or neither) the unit and amount must be provided and that the amount is positive.

You're welcome to set any duration you'd like, but keep in mind that Todoist won't display the duration in the apps if:

• The task has no due date
• The duration unit is "day"
• The duration unit "minute" and the amount is >=1440 (24 h)

[thales-fukuda]

Thanks for the review @pawelgrimm!
I pushed a commit with the changes, please take a look to see if I didn't miss anything.

Also, I was reviewing the SDK types to see if something else is not aligned with the API documentation and I found some stuff. Should I open a new issue or can we discuss it here?

[pawelgrimm]

Looks great! 🚀

Also, I was reviewing the SDK types to see if something else is not aligned with the API documentation and I found some stuff. Should I open a new issue or can we discuss it here?

Let's keep this PR atomic and discuss in a new issue. Feel free to tag me directly!