Bug 32138: Fix OIDC default mapping

Bug 32138: Fix OIDC default mapping

This patch fixes the OIDC default mapping to have the Koha fields on
the left (ie key) and the OIDC standard claim fields on the right (ie value).

1. Apply the patch
2. Go to http://localhost:8081/cgi-bin/koha/admin/identity_providers.pl?op=add_form
3. Choose "OIDC" for "Protocol"
4. Click "Add default OIDC mapping"
5. Note the following is displayed:
{
  "email": "email",
  "firstname": "given_name",
  "surname": "family_name"
}

Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>