Currently JabRef shows eprint in one tab and eprinttype in another

Reason: eprint is configured as "General" field:

Task:

1. Change default preference to contain eprinttype for General:

2. Add preference migration if old preference is

   General:doi;citationcount;crossref;keywords;eprint;url;file;groups;owner;timestamp;printed;priority;qualityassured;ranking;readstatus;relevance
   Abstract:abstract