Change request: Metadata version -> Metadata versions

[josepot]

The current output is misleading, eg:

IMO it should, instead, display the list of supported versions returned by the Metadata_metadata_versions runtime call.

The reason why I'm requesting this change is because during Sub0 I came across a few developers who were under the wrong impression that they wouldn't be able to use Polkadot-API for their parachain, because they didn't know that their parachain supported more Metadata versions other than V14.