localedef: expand the default charmap

POSIX defines a number of other control characters as well as
alternative aliases for some that should be provided in the default set,
so let's go ahead and add those.

Reviewed by: bapt, yuripv
Sponsored by: Klara, Inc.

(cherry picked from commit 3a7ffe206ce7e4741fae26432f6d6e5159207f45)