Feature/ogc 508 replace elastic search by postgres v2

[Tschuppi81]

Please fill in the commit message below and work through the checklist. You can delete parts that are not needed, e.g. the optional description, the link to a ticket or irrelevant options of the checklist.

Commit message

<Module>: <Message>

TYPE: <Feature|Bugfix> LINK: <Ticket-Number> HINT: <Optional upgrade hint>

Checklist

• [ ] I have performed a self-review of my code
• [ ] I considered adding a reviewer
• [ ] I have added an upgrade hint such as data migration commands to be run
• [ ] I have updated the PO files
• [ ] I have added new modules to the docs
• [ ] I made changes/features for both org and town6
• [ ] I have updated the election_day API docs
• [ ] I have tested my code thoroughly by hand
  • [ ] I have tested styling changes/features on different browsers
  • [ ] I have tested javascript changes/features on different browsers
  • [ ] I have tested database upgrades
  • [ ] I have tested sending mails
  • [ ] I have tested building the documentation
• [ ] I have added tests for my changes/features
  • [ ] I am using freezegun for tests depending on date and times
  • [ ] I considered using browser tests für javascript changes/features
  • [ ] I have added/updated jest tests for d3rendering (election_day, swissvotes)