esp32/network_common: Raise a memory error on ESP_ERR_NO_MEM.

This commit changes the error handler for WiFi operations to recognise
out of memory conditions reported by ESP-IDF functions, and report them
as more descriptive exceptions rather than a generic "error 0x101".

The error handler only provided a human-readable error description for
WiFi-specific error codes (codes in the ESP_ERR_WIFI_BASE range), but
WiFi functions are known to return other codes.  Now ESP_ERR_NO_MEM is
covered with a specific error message, making it easier to debug issues
related to running out of ESP-IDF heap.

Signed-off-by: Alessandro Gatti <a.gatti@frob.it>

ports/esp32/network_common.c

@@ -77,6 +77,8 @@ MP_NORETURN void esp_exceptions_helper(esp_err_t e) {
             mp_raise_msg(&mp_type_OSError, MP_ERROR_TEXT("Wifi Would Block"));
         case ESP_ERR_WIFI_NOT_CONNECT:
             mp_raise_msg(&mp_type_OSError, MP_ERROR_TEXT("Wifi Not Connected"));
+        case ESP_ERR_NO_MEM:
+            mp_raise_msg(&mp_type_OSError, MP_ERROR_TEXT("WiFi Out of Memory"));
         default:
             mp_raise_msg_varg(&mp_type_RuntimeError, MP_ERROR_TEXT("Wifi Unknown Error 0x%04x"), e);
     }