Implement Expressif ESP32 & ESP8266 Node Wifi Mesh into ESPHome core

**Describe the problem you have/What new integration you would like**

Node Mesh has been implemented in Zigbee & Z-Wave systems which greatly increases the range and throughput of the network.

This request is to integrate Mesh Network topology into ESPHome nodes.

By scattering nodes across the home, one could create a blanket of BLE repeaters, or even reduce gaps in Wifi node coverage without the use of a separate Wifi AP.

**Please describe your use case for this integration and alternatives you've tried:**

Expressif has released mesh SDK's for the ESP32 & 8266 chipsets. This feature request is to incorporate Wifi mesh into ESPHome to allow greater node range & throughput.

See: https://www.espressif.com/en/products/sdks/esp-wifi-mesh/overview
&
https://randomnerdtutorials.com/esp-mesh-esp32-esp8266-painlessmesh/

**Additional context**

The request names no files, tests, or entry points. Start by reviewing the linked Espressif Wi-Fi Mesh SDK and painlessMesh resources, then inspect ESPHome's existing node and networking architecture; done would require a defined, supported mesh integration for ESP32 and ESP8266 nodes.

Written by the indexing model from the issue text.