Change util methods for standard ES6 ones

[SergioMorchon]

There are a lot of "util" methods present in current Knockout code that are part of the ES6 definitions. They are also implemented in shims, as Babel presets for example. So there is no more need to implement them by our side. Just use the ES6 definition and let the transpilers do the rest. We can use them directly or adapt the inner code to reuse them, but not reimplementing the wheel. I'll list all of them here:

Array

• [ ] arrayForEach https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach
• [ ] arrayIndexOf
• [ ] arrayFirst https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/some
• [ ] arrayMap https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/map
• [ ] arrayFilter https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter
• [ ] makeArray https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/from

  Function

• [ ] bind remove it

  Object

• [ ] extend https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/assign

[brianmhunt]

Thanks Sergio!

Updating the utils is definitely on the TODO.

Instead of the builtins, I've considered importing the lodash utils. I'm on the fence, because lodash typically faster than the builtins, but it is an external dependency ...

I definitely feel like TKO ought to defer to standards + polyfills (e.g. core.js).