Format (§) code for RGB text to build on text component functionality

Seeing as text components now support specifying RGB color codes for text in the recent snapshots, it would be extremely useful for server admins to have this functionality in the form of a format (§) code. This would allow colors to be used in many new places - group prefix/suffixes, chat, signs, holograms, all without having to update plugins, most likely making backwards-incompatible changes, to accommodate for this.

We're currently stuck with 12 non-grayscale colors. Very quickly, we run out. Having another format code would expand this very limited set to practically infinite.