Support for Polish OLED characters

Added support for Polish OLED characters.

- Custom FONT_SMALL ArialMT_Plain_10_PL

- Automatic selection between Polish and Ukrainian/Russian characters mapping depending on the -D OLED_{LANG_NAME} flage

src/graphics/Screen.cpp

@@ -123,7 +123,7 @@ static bool heartbeat = false;
 /// Check if the display can render a string (detect special chars; emoji)
 static bool haveGlyphs(const char *str)
 {
-#if defined(OLED_UA) || defined(OLED_RU)
+#if defined(OLED_PL) ||defined(OLED_UA) || defined(OLED_RU)
     // Don't want to make any assumptions about custom language support
     return true;
 #endif