WIP: Resolve "implement demo from Ulfs tutorial"

Ulfs first tutorial was today (20-may) on https://us04web.zoom.us/j/72779018662?pwd=M094M1JpZHE0MVpaOW8wUDJxYlYzZz09

Recording url: https://cernbox.cern.ch/index.php/apps/files/?dir=/__myshares/OMS%20Tutorials%20(id%3A259096)&

The end goal is to have, in this repository, a working codebase resembling the functionality demonstrated in that tutorial.

Definition of done:

• working, clean, code that produces a panel in an OMS installation
• the panel contains a line chart
• code is very well documented, must be comprehensible to total newcomers to OMS
• documentation is provided in markdown describing any other aspects useful to newcomers
  • what/where is OMS
  • how does OMS work
  • how this code is deployed
• includes SQL code for used DB tables and data (preferably simple demo data)
• unit, integration, and e2e tests wherever possible
• working dockerfile
• CI automatically performs tests
• CI automatically compiles the code
• CI automatically builds dockerfile
• CI automatically builds any 'builder' dockerfiles used to compile the code
• CI automatically deploys a demo instance containing this codebase

Closes #1