Add due tasks badge to dock

[Suzie97]

Problem

Right now there is no way to see scheduled tasks without opening the app.

Proposal

Add an badge to the dock icon showing scheduled tasks.

Prior Art (Optional)

Planner

[Suzie97]

It should be considered whether to show all the scheduled tasks, or the tasks that have passed their due time.

[Chandram-Dutta]

It should be considered whether to show all the scheduled tasks, or the tasks that have passed their due time.

It would be better to show tasks that have passed their due time and task scheduled to end that day