Handle non-UTF-8 in quoting style

[RenjiSann]

Right now, quoting-style uses String::from_utf8_lossy to handle the quoting of given inputs, which replaces the non UTF-8 characters with the replacement character \u{FFFD}.

It may a problem for several utils:

ls

$ touch "`echo -ne 'funky\xffname'`"
$ ls
'funky'$'\377''name'

$ ../../target/debug/ls
funky�name

cksum and hashsum checking

Here, quoting is used to print in stderr when a file is a directory or not found

$ echo -ne `SHA256` (XXX\xffXXX) = e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855' > CHECKSUM

$ cksum -c CHECKSUM
cksum: 'XXX'$'\377''XXX': No such file or directory
XXXXXX: FAILED open or read
cksum: WARNING: 1 listed file could not be read

$ ../../target/debug/cksum -c CHECKSUM 
../../target/debug/cksum: XXX�XXX: No such file or directory # Here, the file should be escaped
XXXXXX: FAILED open or read
../../target/debug/cksum: WARNING: 1 listed file could not be read

There are probably some other places where correctly quoting non UTF-8 characters might prove useful.

[BenWiederhake]

The first part is a special case of #6639.

[RenjiSann]

The first part is a special case of #6639.

Indeed ! I am working on a fix, but this requires a big change to quoting_style.rs, because we are not working with UTF8 String anymore.
My implementation is starting to work, though not yet for the Literal quoting style, which basically does nothing, so its the only case where the output is not a valid UTF-8 string, and I have to change the quoting_style.rs API for it.

The only issue I have so far is that I am making use of slice::utf8_chunks for which I need MSRV >= 1.79, so I guess we'll have to wait.

If you want to take a look: diff

[RenjiSann]

This is fixed by #6882