bug(ls): Time Style not accept abbreviated, acronyms

Start at the uu ls time-style argument handling and reproduce the reported TIME_STYLE=posix-local and abbreviated local cases from the issue. Compare the accepted values with GNU ls behavior; done means the abbreviated and acronym forms no longer produce an invalid-argument error and existing checks still pass.

Hi, uutils mainteners

we saw that in our test

relunsec@relunsec:~/software/coreutils/target/debug$ TIME_STYLE=$'posix-local' ./ls -lah 
ls: invalid --time-style argument 'local'
Possible values are:
  - [posix-]full-iso
  - [posix-]long-iso
  - [posix-]iso
  - [posix-]locale
  - +FORMAT (e.g., +%H:%M) for a 'date'-style format

For more information try --help
relunsec@relunsec:~/software/coreutils/target/debug$ 
relunsec@relunsec:~/software/coreutils/target/debug$ TIME_STYLE=$'posix-local' gnuls -lah | head -c 1000
total 3.2G
drwxrwxr-x   7 relunsec relunsec  463 Sep 19 12:15 .
drwxrwxr-x   4 relunsec relunsec    7 Aug  9 08:41 ..
-rw-rw-r--   1 relunsec relunsec    0 Aug  9 08:38 1o6iHq6D6FKsl7187mIs65fv8LQirsHfB
-rw-rw-r--   2 relunsec relunsec    3 Aug 11 03:42 a
-rwxr-xr-x   1 relunsec relunsec    3 Aug  9 09:44 a@
-rw-rw-r--   1 relunsec relunsec    3 Aug  9 09:44 a~
-rwxrwxr-x   2 relunsec relunsec  77M Aug  9 06:44 arch
-rw-rw-r--   1 relunsec relunsec  13K Aug  9 06:45 arch.d
-rw-rw-r--   1 relunsec relunsec    0 Sep 18 12:12 a.txt
-rw-rw-r--   2 relunsec relunsec    3 Aug 11 03:42 b
-rwxrwxr-x   2 relunsec relunsec  81M Aug  9 06:45 b2sum
-rw-rw-r--   1 relunsec relunsec  13K Aug  9 06:45 b2sum.d
-rwxrwxr-x   2 relunsec relunsec  79M Aug  9 06:45 base32
-rw-rw-r--   1 relunsec relunsec  13K Aug  9 06:45 base32.d
-rwxrwxr-x   2 relunsec relunsec  79M Aug  9 06:45 base64
-rw-rw-r--   1 relunsec relunsec  13K Aug  9 06:45 base64.d
-rwxrwxr-x   2 relunsec relunsec  77M Aug  9 06:44 basename
relunsec@relunsec:~/software/coreutils/target/debug$ 

uu ls expects fully posix-locale it is common to miss the e, and just local, so that will break some scripts that rely on abbreviated time styles