"Enabled" flag added in Helm chart and Postgres templates

[joydipb01]

Description

Addresses Issue 9357 by ensuring that postgres related templates are called upon only when postgres is enabled in the helm chart

Affected Dependencies

List any dependencies that are required for this change.

How has this been tested?

Starting up using helm should be enough to test the change.

Checklist

• [x] I have followed the Contribution Guidelines and Code of Conduct
• [x] I have commented my code following the OpenMined Styleguide
• [x] I have labeled this PR with the relevant Type labels
• [x] My changes are covered by tests