Continue legend overflow on new line

It was brought up that some journals put restrictions on legend size. So, it would be nice to also allow legend text to continue on a new line.

We can set up a toggle on the legend that will either fit all legend text on single line (currently how its done) or continue legend text on a new line when overflow happens.

Start by locating the legend rendering entry point in the JavaScript visualization code and inspect how single-line overflow is currently handled. Add the requested toggle behavior so legends can either remain on one line or continue onto a new line, then verify both display modes with the project's existing checks.

Written by the indexing model from the issue text.