bug(stat): invalid unicode file not escaped, they replaced with U+FFFD

[HackingRepo]

Hi, uutils mainteners

when trying

relunsec@relunsec:~/software/coreutils/src/uu/touch/src$ ../../../../target/debug/stat $'\xC3'
stat: cannot statx '�': Invalid or incomplete multibyte or wide character
relunsec@relunsec:~/software/coreutils/src/uu/touch/src$ gnustat $'\xC3'
gnustat: cannot statx ''$'\303': Invalid or incomplete multibyte or wide character
relunsec@relunsec:~/software/coreutils/src/uu/touch/src$