Add required certifications and create certifications for visiting an event

@ayduns , we are just starting using your extension, exactly what was missing for us. Thanks. I add two new features to this extension. If you like I can make a merge request. You can see it here: https://lab.civicrm.org/david124136468769/certifications/-/compare/main...addcertificationrequired?from_project_id=1674.

1. As you suggested #4 It is now possible to specify required certification types for a group and also for participants of an event. For reporting I added three basic searches below the certifications menu, currently without filters. The requirements for participants are managed by a custom field on the event.
2. The other is to generate certificates automatically for event participants, by a scheduled job. The certification type, is based on a custom field in the event. The certification is generated if the event is finished and participant status is set do “attended”.
3. Certifications can now be linked to an event
4. I also added the “Add Buttons” #8
5. It was also necessary to regenerate files with civix, that civix allows me to create a new entry. (first time I using it, so maybe it is not necessary, don’t know if it have consequences)