[espnow, ethernet, network, openthread, wifi] centralize network initialization for ESP32 (#14012)

Co-authored-by: kbx81 <kbx81x@gmail.com>
Co-authored-by: J. Nick Koston <nick@koston.org>
Co-authored-by: J. Nick Koston <nick+github@koston.org>

esphome/components/network/network_component.cpp

@@ -0,0 +1,33 @@
+#include "network_component.h"
+
+#include "esphome/core/defines.h"
+#if defined(USE_NETWORK) && defined(USE_ESP32)
+#include "esphome/core/log.h"
+#include "esp_err.h"
+#include "esp_netif.h"
+#include "esp_event.h"
+namespace esphome::network {
+
+static const char *const TAG = "network";
+
+void NetworkComponent::setup() {
+  // Initialize ESP-IDF network interfaces and ensure the default event loop exists
+  esp_err_t err;
+  err = esp_netif_init();
+  if (err != ESP_OK) {
+    ESP_LOGE(TAG, "esp_netif_init failed: (%d) %s", err, esp_err_to_name(err));
+    this->mark_failed();
+    return;
+  }
+  err = esp_event_loop_create_default();
+  // ESP_ERR_INVALID_STATE is returned if the default loop already exists,
+  // which is fine since we just want to make sure it exists
+  if (err != ESP_OK && err != ESP_ERR_INVALID_STATE) {
+    ESP_LOGE(TAG, "esp_event_loop_create_default failed: (%d) %s", err, esp_err_to_name(err));
+    this->mark_failed();
+    return;
+  }
+}
+
+}  // namespace esphome::network
+#endif