Feat: end-to-end-security demo

[fhennig]

This is a demo showcasing a bank scenario using as much security as possible :)

Documentation

part of: stackabletech/issues#530

needs stackabletech/release#29

[fhennig]

I simplified the keycloak setup in this kuttl test (for reference): https://github.com/stackabletech/opa-operator/pull/529/files

[NickLarsenNZ]

LGTM

[lfrancke]

Can you please include a link to the documentation on this?

[sbernauer]

Linked the docs in the description (it needs to point to nightly docs)

[lfrancke]

The docs are a bit thin.
Especially under accessability aspects does it not contain any textual description of at least the stack.
Can I please ask you to extend it to include more details on what is contained in the demo?

[lfrancke]

This is waiting for #49