Move showNumber to TS and call showString (#829)

libs/core/shims.d.ts

@@ -130,17 +130,6 @@ declare interface Image {
     //% color=#0078D7 weight=100 icon="\uf00a"
 declare namespace basic {
 
-    /**
-     * Scroll a number on the screen. If the number fits on the screen (i.e. is a single digit), do not scroll.
-     * @param interval speed of scroll; eg: 150, 100, 200, -100
-     */
-    //% help=basic/show-number
-    //% weight=96
-    //% blockId=device_show_number block="show|number %number" blockGap=8
-    //% async
-    //% parts="ledmatrix" interval.defl=150 shim=basic::showNumber
-    function showNumber(value: int32, interval?: int32): void;
-
     /**
      * Draws an image on the LED screen.
      * @param leds the pattern of LED to turn on/off