Provide descriptive text for display when notification previews are hidden

[Deleted user]

Is your feature request related to a problem? Please describe.
I want to prevent my confidential correspondence from being read by bystanders when my phone is locked. Having disabled notification previews to achieve that rendered all ProtonMail notifications indescriptive.

Describe the solution you'd like
From Apple's Human Interface Guidelines:

Provide descriptive text for display when notification previews are hidden. Based on the user's settings, notification previews may be hidden for privacy. In this case, only your app icon and a generic description (Notification is the default description) are shown. To provide the user with sufficient context, your app should provide custom text that succinctly describes notification content, like Friend Request, New Comment, Reminder, or Shipment.

Additional context
Ideally, there should be the name of a mail sender in a notification title, and short text, such as "Mail message" (same as in Mail notifications), underneath it that describes notification content.