Add std.unicode.fmtUtf8 that can handle ill-formed UTF-8
Ill-formed UTF-8 byte sequences are replaced by the replacement character (U+FFFD) according to "U+FFFD Substitution of Maximal Subparts" from Chapter 3 of the Unicode standard, and as specified by https://encoding.spec.whatwg.org/#utf-8-decoder
f6b6b8a4aeRyan Liptak committed on 2/24/2024, 10:04:59 PMparent80508b9