PostgreSQL Passwordless Support

[fangjian0423]

Unit 3 use Connector Service for PostgreSQL passwordless connections.

Unit 4 drop PostgreSQL passwordless connections after use KeyVault as secret management.

Unit 7 don't use PostgreSQL passwordless connections in terraform.

I think all of them should use passwordless connections, it's more security for customers.

[kelwinpa]

@fangjian0423 this PR was created

[selvasingh]

@kelwinpa and @candicenonsense - close this issue?

[candicenonsense]

Closing