Fix: Move WS error handling (#174)

Moves all WS handling of unexpected payloads into the stream to prevent code duplication.

This also prevents non-{Hello,Resumed,Ready} messages from causing a handshake failure, as it seems Discord do not prevent such messages from appearing.

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Co-authored-by: Kyle Simpson <kyleandrew.simpson@gmail.com>

src/events/context/data/disconnect.rs

@@ -90,7 +90,6 @@ impl From<&ConnectionError> for DisconnectReason {
             | ConnectionError::CryptoModeInvalid
             | ConnectionError::CryptoModeUnavailable
             | ConnectionError::EndpointUrl
-            | ConnectionError::ExpectedHandshake
             | ConnectionError::IllegalDiscoveryResponse
             | ConnectionError::IllegalIp
             | ConnectionError::Json(_) => Self::ProtocolViolation,