Add connectors command #8

This is a follow up to #6 and #7.

We should add wp connectors list and wp connectors get commands that uses _wp_connectors_get_connector_settings to display information about the available connectors (name, description, status, api key, auth method, etc).

The plugin slug is available there so we can show whether the connector is installed or not.

See https://github.com/WordPress/wordpress-develop/blob/5f0ac6faf6a1ddd567009fe3a33fb029b6dbcc4a/src/wp-includes/connectors.php#L118 for that code.

We could add tests that install the plugins for the default providers (openai, anthropic, google) and even install a community plugin such as https://github.com/zaherg/ai-provider-for-openrouter and verify that it shows up in the connectors list.