The previous implementation of Styled used chunks that consisted of a
String and a ContentStyle. The current implementation instead stores a
single String and chunks consisting of a ContentStyle and an ending
index.
This implementation may reduce allocations and makes width-related
operations easier, for example getting the width of a Styled with its
whitespace trimmed.
This lets the user restrict the drawable area to a sub-area of the
buffer. This lets the user draw without caring about the absolute
position, and guarantees that no glyphs or glyph parts appear outside of
the drawable area.
