Alerts when cooldowns (medical, i.e.) have fallen below the limit so another item can be taken

[Manuito83]

This probable requires to:

• Add additional parameters to Firestore (e.g.: "drugsNotificationWhenMarginAvail" && "drugsNotificationWhenMarginAvailSent")
• Add additional considerations based on remaining timestamps where applicable
• Add additional lines in Alerts (e.g.: below "Drugs cooldown") to add the option to notify when another item has been taken