Use updated job alert API

Original bug report / Project repo

Changes overview

• The dysfunctional legacy API re-implemented and moved to a new address (apis.embl.de/jobalert);
• Added handling of HTTPO response codes;
• IMPORTANT: the API is now pointing to production Talentlink (there are no job records in the test one).

TODO

• Review changes;
• Unblock test page and make sure job alerts can be set up - you should receive an e-mail from TalentLink;
• Update production accordingly.