add function to retrieve the list of tickets missing some rephrasing

Resolved tickets must either have the release notes summary field filled in or the noRNS tag set. If one is missing, then it needs to be updated.

This will allow to:

1. abort a build if some tickets are missing a rephrasing status
2. send a reminder upfront to rephrase resolved tickets

This could be handled in the releaseNotes.sh script with the md option.

This would allow to preview the release notes, even if they are incomplete showing rephrased summaries and ticket references with actual summaries prefixed with [REPHRASING NEEDED].

In case the rephrasing is not finished an exit code value of 1 is returned else 0.

The check can be disabled with the option --no-check.