Add egress postgres network policy

• Add egress-postgres network policy

Description: Allows for external postgres connections to be allowlisted by network policy.

Upgrade Notices

N/A

Testing

Confirmed that helm template render chart --set 'networkPolicies.enabled=true','postgresql.enabled=false' causes the network policy to be rendered. helm template render chart --set 'networkPolicies.enabled=true' does not cause the egress-network policy to be created.

Notes

Copied from keycloak https://repo1.dso.mil/big-bang/product/packages/keycloak/-/blob/main/chart/templates/bigbang/network-policies/egress-postgres.yaml