Improve PostgreSQL config

[wxing1292]

What changed?

• Include connectAttributes as part of connection string

Why?
connectAttributes was not used

Closes #1208

How did you test it?
Manual test locally

persistence:
  defaultStore: postgres-default
  visibilityStore: postgres-visibility
  numHistoryShards: 4
  datastores:
    postgres-default:
      sql:
        pluginName: "postgres"
        databaseName: "temporal"
        connectAddr: "127.0.0.1:5432"
        connectProtocol: "tcp"
        connectAttributes:
          application_name: temporaltest
    postgres-visibility:
      sql:
        pluginName: "postgres"
        databaseName: "temporal_visibility"
        connectAddr: "127.0.0.1:5432"
        connectProtocol: "tcp"
        connectAttributes:
          application_name: temporaltest

postgres=# SELECT application_name FROM pg_stat_activity limit 1;
 application_name 
------------------
 temporaltest
(1 row)

Potential risks
N/A