Add the ability to set friendly name when using `step certificate p12`

## Hello! - Vote on this issue by adding a 👍 reaction - If you want to implement this feature, comment to let us know (we'll work with you on design, scheduling, etc.) ## Issue details Provide the ability to override the friendly name when using `step certificate p12`. ## Why is this needed? Sometimes we get specific requests for friendly names in pfx packages. With `openssl pkcs12` we can provide the `--name` parameter. I can only assume these friendly names are used as part of some other process where having the default of ` - ` is unacceptable.