t/loc_tools.pl: Extract out finding locales from locale.t

t/loc_tools.pl: Extract out finding locales from locale.t

Several different test files need to find the locales on the system, and
each currently has rolled its own methods to do that.  This commit
creates a new file t/loc_tools.pl which is designed to be a common
place for these tools.

lib/locale.t did the most thorough job of finding locales, so
t/loc_tools.pl is built upon what it had, which is now deleted from
locale.t.

The code in t/loc_tools.pl was copied from lib/locale.t with white space
changes and changes to make this be a subroutine, and helper functions
renamed to begin with an underscore, and changing the hard-coded list to
be in a DATA section so it doesn't have to be actually used unless
necessary.