FR: todo button to show badge for upcoming items

[saya6k]

trafficstars

Currently, the numbers below the button title indicate the total count of items.

However, adding a red badge for todo button could enhance usability.

When combined with a due date, it can function as a simple to-do planner.

The badge should display the count of items that match options.

In button, config should show options such as:

• Show badge for items with a due date: boolean
• Show badge for upcoming items: int (e.g., if it's 3, count items with a due date within 3 days)
• Show badge for to-dos that have no due date: boolean

Modify the to-do button to display this badge.