Add a post-login message to promote personal access tokens

[amineck]

What I did

• Add a post-login message to promote Personal Access Tokens https://docs.docker.com/docker-hub/access-tokens/
• Message will only appear if:
  1- User is using default registry
  2- User successfully logged in
  3- User is not using a Personal Access Token

> docker login -u amineck
Password:
Login Succeeded

Logging in with your password grants your terminal complete access to your account.
For better security, log in with a limited-privilege personal access token. Learn more at https://docs.docker.com/docker-hub/access-tokens/

[ndeloof]

As this is a compose-cli only "feature", i.e. not intended to move into compose.v2, pat_suggest.go should not be part of pkg and could just be hosted within cli package

[amineck]

Sure @ndeloof, I was trying to follow https://github.com/docker/compose-cli/blob/main/pkg/utils/scan_suggest.go