esp_http_client: add flush response

Signed-off-by: Shubham Kulkarni <shubham.kulkarni@espressif.com>

Merges: https://github.com/espressif/esp-idf/pull/5845
Closes: https://github.com/espressif/esp-idf/issues/5814

components/esp_http_client/include/esp_http_client.h

@@ -524,6 +524,21 @@ bool esp_http_client_is_complete_data_received(esp_http_client_handle_t client);
 
 int esp_http_client_read_response(esp_http_client_handle_t client, char *buffer, int len);
 
+/**
+ * @brief       Process all remaining response data
+ *              This uses an internal buffer to repeatedly receive, parse, and discard response data until complete data is processed.
+ *              As no additional user-supplied buffer is required, this may be preferrable to `esp_http_client_read_response` in situations where the content of the response may be ignored.
+ *
+ * @param[in]  client  The esp_http_client handle
+ * @param      len     Length of data discarded
+ *
+ * @return
+ *     - ESP_OK                 If successful, len will have discarded length
+ *     - ESP_FAIL               If failed to read response
+ *     - ESP_ERR_INVALID_ARG    If the client is NULL
+ */
+int esp_http_client_flush_response(esp_http_client_handle_t client, int *len);
+
 /**
  * @brief          Get URL from client
  *