Fix Black and White Typo (#2138)

* Fixed typo: Back->Black

* Added Upgrade Rules to fix spelling

* Removed extra isEmpty

* Added previous BackAndWhite to allow for compilation of old scripts

libs/core/_locales/core-strings.json

@@ -69,7 +69,7 @@
   "Dimension.Z|block": "z",
   "Direction.Left|block": "left",
   "Direction.Right|block": "right",
-  "DisplayMode.BackAndWhite|block": "black and white",
+  "DisplayMode.BlackAndWhite|block": "black and white",
   "DisplayMode.Greyscale|block": "greyscale",
   "EventCreationMode.CreateAndFire": "MicroBitEvent is initialised, and its event handlers are immediately fired (not suitable for use in interrupts!).",
   "EventCreationMode.CreateOnly": "MicroBitEvent is initialised, and no further processing takes place.",

libs/core/enums.d.ts

@@ -416,6 +416,8 @@ declare namespace control {
 
     declare const enum DisplayMode {
     //% block="black and white"
+    BlackAndWhite = 0,  // DISPLAY_MODE_BLACK_AND_WHITE
+    //% blockHidden=true
     BackAndWhite = 0,  // DISPLAY_MODE_BLACK_AND_WHITE
     //% block="greyscale"
     Greyscale = 1,  // DISPLAY_MODE_GREYSCALE

libs/core/led.cpp

@@ -2,6 +2,8 @@
 
 enum class DisplayMode_ {
     //% block="black and white"
+    BlackAndWhite = DISPLAY_MODE_BLACK_AND_WHITE,
+    //% blockHidden=true
     BackAndWhite = DISPLAY_MODE_BLACK_AND_WHITE,
     //% block="greyscale"
     Greyscale = DISPLAY_MODE_GREYSCALE,