Implement Wrapping Text and Line Breaks for Text Component

Unlike doing this for the title component where switching runs has the potential of changing the size of your layout, for the text component we can very uncontroversially implement line breaks and text that word wraps into multiple lines. We most likely either only want to do it for centered text. There may be ways to extend it to left / right mode too, but an initial implementation could just ignore that case. The implementation would use `xi-unicode` for the line breaking algorithm. It gives you mandatory and optional line breaking opportunities. It remains to be seen if we want a setting (or multiple) for word wrap mode.

Locate the Text component and inspect how the title component currently handles runs, layout, and line breaks. Review xi-unicode's mandatory and optional line-breaking opportunities, then clarify whether the first version supports centered text only and whether wrapping needs a setting; done requires an agreed behavior for those choices.

Written by the indexing model from the issue text.