Move out Passwords and other ENV variables of `Deployment.yaml`s.

[agentmilindu]

https://github.com/scorelab/Bassa/blob/b7668b90fc4e703a3313e21e62d6115b9fbd5e1c/scripts/kubernetes/manifests/api_and_aria2c/deployment.yml#L30

https://github.com/scorelab/Bassa/pull/828/files#diff-16a3a975467f18ae05c8a74a608e5ad0R24-R30

env:
        - name: BASSA_DB_NAME
          value: 'Bassa'
        - name: BASSA_DB_USERNAME
          value: 'bassa'
        - name: BASSA_DB_PASSWORD
          value: 'bassa@1234'

We are using these in multiple pods, better we move them out and especially the secrets.