Translation updates

[taniwallach]

Updates to the translation files. Relevant sincer #2 was merged.
Among the more important changes is the change from "Show correct answers" to "Show Correct Answers".
Branch was rebuilt on top of the current version of develop.

[taniwallach]

For the record, as explained in https://github.com/openwebwork/renderer/blob/main/docs/make_translation_files.md the pot file can be updated using:

cd lib
xgettext.pl -o WeBWorK/lib/WeBWorK/Localize/standalone.pot -D PG/lib -D PG/macros -D RenderApp -D WeBWorK/lib RenderApp.pm

And then a partial update to the translation files can be done via:

cd WeBWorK/lib/WeBWorK/Localize/
find . -name '*.po' -exec bash -c "echo \"Updating {}\"; msgmerge -qUN {} standalone.pot" \;

and then the translated files need to be reviewed.

[drgrice1]

A script needs to be added that takes care of the po and pot file update.

Also note that with the restructuring in #7 the location of the po/pot files will change (no more lib/WeBWorK/lib/WeBorK!).