feat: omit .secret field, set app password in advance

[chaospuppy]

Description

This PR will allow users to specify an app password in advance, or default to a random password if a password is not provided. Additionally, because the reuse of an existing secret was taking precedence over the random password (to avoid changing the secret every time you deploy), we check to see if a password has not been provided and there is an existing secret, in which case the password will not change between deployments.

Lastly, the top-level .secrets key is deprecated, but is left in the upstream chart, resulting in a pointless example secret called myminio-env-configuration being created which made troubleshooting more confusing.

Related Issue

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Other (security config, docs update, etc)

Checklist before merging

• Test, docs, adr added or updated as needed
• Contributor Guide Steps followed