Hide app bars on scroll

**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