Internal tcp_transport functions could now use custom socket operations.
This is used for WebSocket transport, when we typically wait for clean
connection closure, i.e. selecting for read/error with expected errno or
recv size=0 while socket readable (=connection terminated by FIN flag)
transport_ws can now be read multiple times in a row to read frames larger than the buffer.
Added reporting of total payload length and offset to the user in websocket_client.
Added local example test for long messages.
Closes IDF-1083
user_context was missing from websocket event data, added. Also added the websocket client handle to the event data.
Removed unused event data struct.
Closes: IDF-1271
tcp-transport component did not support wait forever. this update uses value of -1 to request this state.
websocket client uses timeouts in RTOS ticks. fixed recalculation to ms (including special value of -1) to use correctly tcp-transport component
Closes https://github.com/espressif/esp-idf/issues/4316
