Update GeckoView to at least 72.0

[Daddoon]

Update GeckoView to at least 72.0.

Current version is working fine, but remote debugging of GeckoView is not possible on this version, as WebIDE is deprecated and not shipped on recent versions of Firefox.

The new behavior with about:debugging option need at least GeckoView 72.0 in order to user this new way of doing it.

• [ ] Update GeckoView
• [ ] Update Bindings generation
• [ ] Update GeckoView delegates code if needed
• [ ] Update doc section about debugging

[Daddoon]

As it is still possible to install Firefox 67 with WebIDE for debugging, this issue is less a prioritary