Ability to sort emails - unread emails at the top, and read ones at the bottom.

[AV-037]

Prerequisites

• I have searched for duplicate or closed feature requests
• I have searched for plugins that provide already provide the feature

Proposal

Add the ability to sort emails in this way - unread emails are placed at the top, and read ones at the bottom.

Motivation and context

It is not convenient to enter unread emails separately, since read emails should always be at hand. It takes several hours to process some emails and they go to the next page and get lost from sight.

[alecpl]

There's a button in the search bar to show only unread email. It's a quick one-button action.

Implementing a custom sorting order would not be trivial, and imo not worth the effort.

Similar request: #8760.