PubSubItem deserialize

[AmazingGame]

…ng in errors.

json example:
"{"jsonrpc":"2.0","id":268,"result":null,"error":{"code":-32000,"message":"tracing failed: fee cap less than block base fee: address 0x4a4BA8a759e7217a1ff38749Aa6E73564C1D8a01, gasFeeCap: 11470668621 baseFee: 11484931392"}}"

If the json response contains both result and errors, it's better to return errors instead of "response must be a success/error or notification object"

Also, after returning "de::Error::custom", in

  pub async fn handle_text(&mut self, t: String) -> Result<(), WsClientError> {
         trace!(text = t, "Received message");
         match serde_json::from_str(&t) {
             Ok(item) => {
                 trace!(%item, "Deserialized message");
                 let res = self.handler.unbounded_send(item);
                 if res.is_err() {
                     return Err(WsClientError::DeadChannel)
                 }
             }
             Err(e) => {
                 error!(e = %e, "Failed to deserialize message");
             }
         }
         Ok(())
     }

An error should be returned instead of just printing the error, which would cause the request to wait indefinitely.

PR Checklist
[x ] Added Tests
[x ] Added Documentation
[x ] Breaking changes

[DaniPopes]

LGTM, waiting on @prestwich