Console.AnsiSourceHandling of ansi codes.
printf and eprintf do not emit OSC 8 hyperlink escapes: any `Url _ attributes in style are silently dropped. Use string_with_attr or output_string if you need hyperlink support.
output_string and output honor `Url _ attrs by wrapping the output in OSC 8 hyperlink escapes when the terminal is color-capable.
Create a string with embedded SGR and OSC 8 formatting codes.
See Ansi_kernel.Attr.t for the semantics of each attribute; in particular, `Url _ wraps string in an OSC 8 hyperlink escape.
Raises if the URL contains control characters.