All sample parts: Save previous sample inputs

In later versions, login will be required anyway ->so previous sample inputs per grammar/schema could easily be saved with the user account.

DB Schema (id, fkeyid, text, timestamp), just query by any fkeyid, order by timestamp and fill some selector accordingly

(from redmine: issue id 320, created on 2018-01-22tgradl, closed on 2018-01-22)

• Relations:
  • relates #329 (closed)