Hide app bars on scroll

[aeharding]

Is your feature request related to a problem? Please describe.

App bars are always visible. This reduces space for content.

Describe the solution you'd like

Option to enable auto hide of app bars when scrolling down.

Describe alternatives you've considered

A bigger phone 📱

Additional context

Apollo had this, and other apps also have this.

https://github.com/ionic-team/ionic-framework/issues/23816