Add support for converting arbitrary BBCode colors to truecolor ANSI escape codes in print_rich()

[Swarkin]

Tested versions

Present in all 4.x docs,
haven't checked 3.x.

System information

N/A

Issue description

The docs explicitly say only these colors are supported in print_rich:

even though all others also seem to be working fine.

Steps to reproduce

print_rich('[color=tomato]tomato color![/color]') - Works fine

Minimal reproduction project (MRP)

N/A

[bruvzg]

Docs are correct, color=tomato will only show in the editor log (since it's RichTextLabel and support all colors, and other RTL features like img), but won't show in the OS terminal.

[Calinou]

I was working on implementing arbitrary color code conversion to truecolor ANSI escape codes, but I couldn't get it to work yet.

[Swarkin]

Docs are correct, color=tomato will only show in the editor log (since it's RichTextLabel and support all colors, and other RTL features like img), but won't show in the OS terminal.

Oh okay I wasn't aware that this was related to the terminal! The fact about bbcode to ansi conversion is only mentioned a bunch of lines below so I thought that it applied to the Godot output.