Bring back sign text formatting (previously the § symbol)

We should be able to italicize, bold, and perform other formatting to text (such as with the § symbol until recently) outside of only coloring it with dye. I've read that many users who attempted to do this in Java and Bedrock have had the feature removed. It should be re-implemented as it would help add to the immersion of players who focus on narratives and write books/manuals in-game, as well as those who want more easily readable signs.