Add extra generic configuration options to Helm charts

We should expand our Helm charts to support some generic configuration options to make them more flexible. Specifically:

• resources (this should replace what we currently have with the resource limits)
• pod.extraSpec
• securityContext
• extraEnv
• extraVolumes
• global.extraObjects

All of these are also supported by the eos-charts, so implementing this will be very straightforward. It will make the Helm charts significantly more configurable from a user perspective.

Additionally, the names should be defined in a bit smarter way: <release>-<pod name>