Add support for setting securityContext and affinity/anti-affinity rules

[sreis]

securityContext

Due to regulatory constraints and to support stricter kubernetes environments, for example, ones where OPA Gatekeeper is deployed with any of the following policies:

• https://open-policy-agent.github.io/gatekeeper-library/website/validation/allow-privilege-escalation
• https://open-policy-agent.github.io/gatekeeper-library/website/validation/read-only-root-filesystem
• https://open-policy-agent.github.io/gatekeeper-library/website/validation/seccomp

We need an API to set up the securityContext of the pods the operator creates to match the security requirements of certain environments.

Affinity/Anti-Affinity rules

These rules allow for more flexible pod scheduling and improved node utilisation. It would be nice to have an API to set this on the pods.

[mkhaas]

Thanks, we will add it in our next release.