feat(backgroundjob): Schedule job after <timestamp>

[ChristophWurst]

Summary

For a planned execution in the future. Avoids a job that picked up again and again until it's time has come.

Credits go to

server/apps/dav/lib/BackgroundJob/UserStatusAutomation.php

Lines 174 to 177 in f8f4370

	$query->update('jobs')
	->set('last_run', $query->createNamedParameter($timestamp, IQueryBuilder::PARAM_INT))
	->where($query->expr()->eq('id', $query->createNamedParameter($this->getId(), IQueryBuilder::PARAM_INT)));
	$query->executeStatement();

and @nickvergessen.

TODO

• Adjust API

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
  • feat(devmanual): Schedule background jobs documentation#11157
• Backports requested where applicable (ex: critical bugfixes)

[nickvergessen]

Then time to squash and merge?