fix(websocket): prevent connection abort on write timeout (IDFGH-16792)

[gabsuren]

Note

Prevents unintended disconnects when a send operation times out without an underlying socket error.

• In esp_websocket_client_send_with_exact_opcode, set errno = 0 before esp_transport_ws_send_raw and, if it returns wlen == 0 on the first chunk with finite timeout and errno == 0, return early (no abort) instead of treating it as a fatal error.
• Keeps connection intact and avoids calling esp_websocket_client_abort_connection on benign write timeouts; no API changes.

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[euripedesrocha]

Could you double-check errno value when we time out on write? LWIP layer sets it to EINPROGRESS(119).

Another thing that I'm missing is the return of widx here, we are in between write but testing for zero. We're changing the return for partial write but why we don't have any update on the call site for the function? Does it impact user code after this change?