Suggestion: add horizontal scrollbar for long error messages

[Alseidon]

Hi,

When trying out new packages, I often do so in a Pluto notebook for convenience and clarity. However, the error messages often are too long (especially the method matching messages like the one below)

It would be convenient to be able to scroll horizontally to see these outputs. At the moment, I am selecting and dragging the text to make text appear, but it's not the most practical method ever...

(another point about error messages I guess, but maybe adding syntax highlighting to them like in the REPL would be awesome)