URN plugin for 3.4

[bozana]

Adapt URN plugin for 3.4

The issues found (s. also #6293):

• The user can choose how URN suffixes should be: default, custom pattern and custom suffix (input field where the user enters the whole suffixes manually).
  Then there is also setting if the check number should be used. If selected, the check number should be added to the URN, no matter what suffix option the user has chosen.
  Currently, adding check number at the end of an URN is only considered for custom suffixes, when an input field is used. Then there is possibility for the user to add the check number at the end of the URN. This is implemented in that FieldUrn.js and FieldUrn.php.
  But if the user has chosen default suffixes (or a custom pattern suffixes) then the URN is calculated based on the patterns but there is no check number at the end. For these suffixes the FieldPubId is used, and the check number is not considered there.
• ClearIssueObjectsURNs does not function
• Not able to save the URNs
• Publish preview in OMP does not consider all objects
• Publication should be used instead of Submission
• Old/unused code exists

PRs

• pkp/pkp-lib#8940 fix clearIssueObjectsPubIds and saving URNs #8943
• pkp/pkp-lib#8940 consider urnCheckNo setting ojs#3884
• pkp/pkp-lib#8940 fix checkDuplicate ojs#3898
• pkp/pkp-lib#8940 consider urnCheckNo setting, fix publish preview omp#1396

[bozana]

@NateWr, could you please take a look at the PR? When everything OK I will add the issue number to the commit message and PR title... Thanks a lot!
I would then in the same way solve it for the stable-3_3_0 (s. #6293)