Bug 35538: Sort OPAC self registration library list by library name

Bug 35538: Sort OPAC self registration library list by library name

This patch modifies opac-memberentry.pl so that the list of libraries is
sorted by library name instead of library code.

To test, apply the patch and restart services.

- If using the default testing data you'll have to go to Administration
  -> Libraries and edit one or more libraries so that the library name
  is alphabetically different than the library code. e.g. Centerville ->
  Zanzibar.
- Go the OPAC and click "Create an account" (requires the
  PatronSelfRegistration system preference).
- Under "Home library," the dropdown of libraries should be ordered by
  library name.

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Emily Lamancusa <emily.lamancusa@montgomerycountymd.gov>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>