add postgres (source and destination) field titles

[jrhizor]

This removes the need for the locales hack which hardcodes some of these values as a special case:

  "form.postgres_host": "Host",
  "form.postgres_port": "Port",
  "form.postgres_username": "User",
  "form.postgres_password": "Password",
  "form.postgres_database": "DB Name",
  "form.postgres_schema": "Schema",

Once this is approved I'll build and push the connector so the build will pass here.

[jrhizor]

Fixed merge issues and building/publishing source-postgres and destination-postgres.

Once those are pushed to Docker Hub I'll make sure the image checker condition passes and merge.