Improve local user experience for User Credentials

[TimurSadykov]

This is part of the bigger work go/simplified-local-adc

User Credentials are now recommended for local development per go/mitigating-cloud-auth-risk

However, some errors and warnings still refer to service accounts (see section 1.2 of the go/simplified-local-adc):

1. When user does not have credential setup, we do not recommend setting up service account, rather we redirect to a new ADC setup page.
2. We show warning about user credentials only if production environment is detected

Reference Java fix: googleapis/google-auth-library-java#1172

[wangyutongg]

For item 2, Python shows the warning message when user credentials are used AND quota project is missing. This could happen in both prod and local dev environment.