Emoji picker

[BurntimeX]

A picker for emoji as a tab below the editor to simplify the insertion of emojis (especially on non-mobile devices).

The graphics of the respective operating system should be used to display the emojis so that we do not have to rely on third-party libraries.

As emojis are somewhat redundant to the existing smiley function, they could replace the smiley function in the long term. For the time being, I prefer to set the smiley function to "off" in the default installation.