Consider adding a feature that allows semantic coloring for the current split

:wave:

I'm working through delta split times changing color when behind/ahead of PB.
I'm using ColumnSettings to create a +/- column to show the delta in a column next to the time and I'm expecting to get back a SemanticColor when the column state updates.
However, it seems to only be returning SemanticColor::Default, assuming its being nullified by `is_live` to only show Default in the following code:

https://github.com/LiveSplit/livesplit-core/blob/master/src/component/splits/column.rs#L273

I'd love to know if I'm approaching this incorrectly,if you need more information, or if I'm on to something!

_(It's very early in the morning, so I am probably just missing something)_

Thanks!

Start in src/component/splits/column.rs around line 273 and trace how is_live affects the SemanticColor returned for column state updates. Clarify the intended coloring for the current split, then implement the behavior and verify that a +/- delta column can receive the expected non-default color.

Written by the indexing model from the issue text.