Demo setup/generators supporting different setup scenarios

[sleidig]

In practice, we are running multiple demo sites for different use cases (e.g. education, health, vocational training). However, the code only supports a single demo setup (config-fix.ts) and the demo data generator services have hard-coded parameters on what to generate. As a workaround, other demo systems are actually run in "synced" mode and cannot auto-generate new data every time a user visits the site.

Requirements / Suggested implementation:

• [ ] allow to put a file into assets folder demo_entities.json that contains docs to be saved into the database in demo mode (after the demo generators ran?)
• [ ] (advanced, maybe later) configure some parameters for the demo data generators through the config (so that demo notes can talk about health instead of school topics in another scenario, for example)

Sample demo_entities.json:

{
"docs": [
    {
      "_id": "Config:CONFIG_ENTITY",
      "otherField": "xyz"
    },
    { /* other doc to be saved using `_bulk_docs` */ }
]
}

[sleidig]

This is actually a more important problem now, because keycloak login (which is required now) doesn't allow to use the app in an iframe (which we are doing to display the username + password to website visitors).

Current demos are:

• https://demo.aam-digital.com (primary, part of code base)
• https://demo2.aam-digital.com (sports 4 development
• https://demo3.aam-digital.com (vocational training)
• https://demo-health.aam-digital.com (health)