v3.240510

Add automatic handling of failed DBS migration and restructuring of Publisher code to put functions common to Publisher_schedd and Publisher_rucio in Publisher(Dbs)Utils

Also a minor fix to REST

List of changes:

What's Changed

• Fix failed migration handling 8382 by @belforte in #8386
• fix "created" value in FMD retriecal. Fix #8388 by @belforte in #8390
• move common code from PubMaster* to PubUtils. Fix #8387 by @belforte in #8392

Full Changelog: v3.240508...v3.240510

Validation: #8393