Support Infisical CLI listing secret attributes only without their secret values

[tommyli]

Hi Infisical team! 👋

The Infisical API supports viewSecretValue when listing secrets but there's no such option in Infisical CLI. Sometimes, it's just handy to script things when using the CLI. Right now, we could use infisical secrets to list all the key=value pairs and then only keep the keys but it's even safer to just retrieve the key names if that option was supported.