experimental support for some special boards

- show VBAT pin (if board definitely has that feature)
- some WROVER board have cross-connection between GPIO 25/27 and PIN 16/17
- experimental support for boards that have NEOPIXEL_I2C_POWER

wled00/wled.cpp

@@ -393,6 +393,11 @@ void WLED::setup()
     pinMode(NEOPIXEL_POWER, OUTPUT);
     digitalWrite(NEOPIXEL_POWER, HIGH);
   #endif
+  #ifdef NEOPIXEL_I2C_POWER
+    pinManager.allocatePin(NEOPIXEL_I2C_POWER, true, PinOwner::Relay);  // just to ensure this GPIO will not get used for other purposes
+    pinMode(NEOPIXEL_I2C_POWER, OUTPUT);
+    digitalWrite(NEOPIXEL_I2C_POWER, HIGH);
+  #endif
 #endif
 
   USER_PRINTLN();