Add `haserrormsg` boolean attribute to jobset API response

Dependencies

• [2] FRTDCC6I Extend the jobset API response
• [3] BKOIYITR added some json responses

Change contents

• replacement in src/lib/Hydra/Controller/API.pm at line 90
  [2.288]→[2.288:328](∅→∅)
  − errortime => $jobset->errortime
  [2.288]

  [3.2922]
  + errortime => $jobset->errortime,

  + haserrormsg => $jobset->errormsg eq "" ? JSON::false : JSON::true