Remove command-line password usage

[mmulvanny]

Description

This PR configures Kubernetes pods with environment variables that redis-cli uses for authentication, and removes command-line authentication from everywhere that redis-cli is executed by the operator. This removal of command-line auth is controlled by a feature flag.

Fixes #1513

Type of change

• Bug fix (non-breaking change which fixes an issue)

Checklist

• Tests have been added/modified and all tests pass.
• Functionality/bugs have been confirmed to be unchanged or fixed.
• I have performed a self-review of my own code.
• Documentation has been updated or added where necessary.

Additional Context