Easier/better way to revert Views' settings

Description of the need

When a Views' setting (e.g. Header) has been overridden for the current display, it's not easy/obvious how to revert it to match the other displays, especially if it's empty.

For example:

1. Create a new view
   • Go to /admin/structure/views/add
   • Enter a name then click 'Continue & configure'
2. Override the header
   • Click 'Add' next to Header
   • Change For to 'This page (override)'
   • Tick 'Global: Text area' and click 'Add and configure header'
   • Click 'Apply (this display)'
   • Click 'Global: Text area' under Header
   • Click 'Remove'

The header is now overridden, but empty. The only option is 'Add', but if we click that and then change For to 'Revert to default' and click 'Add and configure header', nothing happens. So we need to add something first, but even then we need to go to the second screen where we configure whatever we added before the 'Revert to default' option takes effect.

Proposed solution

I propose adding a new option to the drop-button for reverting to default:

This would only be available for overridden settings obviously.