Add reminders for cycles

[arnowelzel]

When a calculated cycle has started, the user should be reminded to check if the start date is correct and indicate the new start of the cycle. This should be repeated twice: once one day after the calculated start and a second one four days later if there is still no manual entry.

Example:

Based on the past cycles the next calculated start date is 2023-12-10.

If the user does not set the day as "period has started", then there will be a reminder on 2023-12-11, 05:00 to check if the day before was the start of the cycle as calculated or not. If that reminder is just closed without any further action a second reminder will be displayed on 2023-12-14, 05:00.

Todo:

• Check how to implement scheduled reminders
• Whenever a cycle start is added or removed, update scheduled reminders