feat: add options to Helm chart to load Trivy config from custom configmap or secret

[kimdre]

Description

The helm chart already provides operator.valuesFromConfigMap and operator.valuesFromSecret keys to set environment variables for the operator from a configmap or secret.
This PR adds this feature also for the trivy configuration, e.g. to set a Proxy from external secret.

trivy.valuesFromConfigMap will overwrite values in the following order:

1. trivy-operator-trivy-config default ConfigMap
2. trivy-operator-trivy-config Secret generated by the Helm Chart

trivy.valuesFromSecret will overwrite values in the following order:

1. trivy-operator-trivy-config default ConfigMap
2. trivy-operator-trivy-config Secret generated by the Helm Chart
3. trivy.valuesFromConfigMap ConfigMap (if specified)

Related issues

• Close Helm Chart valuesFromSecret for trivy #2172

Checklist

• I've read the guidelines for contributing to this repository.
• I've added tests that prove my fix is effective or that my feature works.
• I've updated the documentation with the relevant information (if needed).
• I've added usage information (if the PR introduces new options)
• I've included a "before" and "after" example to the description (if the PR is a user interface change).

[CLAassistant]

All committers have signed the CLA.

[chen-keinan]

@kimdre lgtm 🚀 thank you for the contributions