Improvements for deploying non-demo chart

[chrisburr]

The main change here is:

• Switch to using HTTPS for the demo
• Use helm hooks + batch jobs to initialise the CS/DBs/secrets

I chose this route based on researching various helm charts which can deploy fully featured applications and this seems like the most sensible approach. Most notably GitLab seems to do quite a nice job of providing everything in the helm chart and the documenting how to make it production suitable for various scenarios.

Some standardisation and clean up is needed but I think this is a enough for now. For example:

• Make diracx-demo-init-sql wait for the DB to be ready rather than failing
• Harmonise the values.yaml
• Use something like https://nip.io/ so we always have a host name
• If we're using a custom CA and https://nip.io/ we could think about removing the use of node port
• Figure out how to deploy to k3s
• Move the ingress controller from the demo script to the helm chart