[Legend Statistics] Inline format

[mbondyra]

With #2426 we introduced a tabular version for Legend Statistics. We want to followup with the inline version. Here are the requirements:

Inline format

Values follow the data series name, for each data series columns header are repeated. We use a : char to separate them

and for partition chart (to introduce at some point):

Legend sizing, truncation, line wrapping

format	position	size	scroll	wrap/truncate
inline	left/right	clamp(series + values, 1/2parent)	scrollable vertically	wrap to multi lines, no truncation
inline	top/bottom	full chart size	vertical scroll, items float left	wrap to multiline, no truncation