Trying to fix search indexing issues

This is what I meant when we were talking on mumble :)

ToDo's:

- [ ] I guess it's displaced in `Automator`, where to put?
- [ ] Why not move the poor man's cron to the terminate hook too?
- [ ]  Testing (especially @rightvision should with his problematic search index size [or send me a dump, I'll do it then])

@contao/workgroup-core @tristanlins @discordier @ausi