Support advanced UART customization (#4465)

* Add methods to get hardware uart details.

* Fix `setRxBufferSize` error.

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Co-authored-by: Your Name <you@example.com>

esphome/components/uart/uart_component_esp32_arduino.h

@@ -28,6 +28,9 @@ class ESP32ArduinoUARTComponent : public UARTComponent, public Component {
 
   uint32_t get_config();
 
+  HardwareSerial *get_hw_serial() { return this->hw_serial_; }
+  uint8_t get_hw_serial_number() { return this->number_; }
+
  protected:
   void check_logger_conflict() override;