Improve mobile experience

[neSpecc]

• support inline toolbar
• remove taps highlighting
• fix autocomplete overlaying of Toolbox
• improve UX details

[ohsik]

Currently the entire UI gets hidden behind keyboard on Safari iOS. Does it possible to place UI right above the keyboard if activated.

Ideal behavior on mobile if possible.

[tkaravou]

The editor doesn't work at all on iPad on both Safari and Chrome. You are able to type and use the native commands that IOS has such as bold and underline. However, you can't use any other inline tools. There is no link button for example.

Of note, I'm using the keyboard folio with the on-screen keyboard disabled and I still don't see the toolbar anywhere.

[gohabereg]

Resolved by #826