overloads to support colorizing compiled format strings

[moshelooks]

Adds a new header compile-color.h with overloads of format, format_to, and print to support passing in a text_style together with a compiled format string.

I did a bit of refactoring in color.h to support this via a new detail::apply_style() function because otherwise it would need a bunch of copy-pasting into the new header.

It's generally great that fmt splits functionality across headers so you only pay for what you use. But here it's maybe unfortunate because you can include both color.h and compile.h and still be unable to colorize compiled format strings with compile-color.h.

I had the idea of in e.g. color.h doing something like

#ifdef FMT_COMPILE_H
#include "compile-color.h
#endif

and likewise in compile.h with #ifdef FMT_COLOR_H but want to see if you have other/better ideas first or maybe just want to leave it as-is.

Best, Moshe

[vitaut]

Thanks for the PR but usually it doesn't make a lot of sense to combine format string compilation with colored output. If you really want to do it you can use fmt::styled (https://www.godbolt.org/z/W8Pqb4Ps9) or define your own output functions.