rework rta-makedata to write tests in a chosen database

[dothebart]

Scope & Purpose

We should now create the test data in the collections that we have calculated.

• [ ] :hankey: Bugfix
• [x] :pizza: New feature
• [ ] :fire: Performance improvement
• [ ] :hammer: Refactoring/simplification

Checklist

• [ ] sidelining PRs
  • [ ] ArangoDB Pullrequest
  • [ ] RTA Pullrequest