Roam OCPI: Support of real-time authorization and multiple keys per contract_id

We’ve added support for real-time authorization of locally started sessions. This allows you, for example, to pre-authorize a user’s payment method and then allow or deny the session start based on the result. We have also added support for multiple keys per contract_id, so your organization can be configured to either only allow one key or multiple keys per contract_id. For details, see Tokens module.