Endpoint query parameters omit key

I’ve noticed that none of the endpoints in the OpenAPI specification contain `key` as a query parameter. Given that `key` is required in order to interact with the API successfully, I believe that it should be added to the list.

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Thanks!

Inizia individuando le definizioni degli endpoint OpenAPI e verificando come sono rappresentati i parametri di query. Determina quali endpoint richiedono il parametro `key`, aggiorna i relativi elenchi di parametri e verifica che la specifica lo includa in modo coerente.

Scritto dal modello di indicizzazione a partire dal testo della issue.