add translatable ariaLabel to block dropdown items

[riknoll]

redo of #11399

adds a translatable aria label to dropdown values in blocks. that includes things like enums and getters/setters that are automatically converted into dropdown lists.

this works just like the localization of the block string and jsdoc string; it gets overwritten in the symbol info when we localize the APIs so there is no need to call rlf when referencing it.

you can also translate it on the block definition itself like so:

//% weight=100 color=#0fbc11 icon=""
namespace custom {
    export class MyClass {
        //% blockSetVariable="mySprite"
        //% blockCombine block="x" callInDebugger
        //% ariaLabel="hello"
        //% ariaLabel.loc.ru="nyet"
        get x(): number {
            return 0;
        }

        //% group="Physics" blockSetVariable="mySprite"
        //% blockCombine block="x"
        //% ariaLabel="hello"
        //% ariaLabel.loc.ru="nyet"
        set x(value: number) {

        }
    }
}

(obviously i don't speak russian)