Replace es6-promise module with native-promise-only module

[archmoj]

As mentioned in #897 (comment) the [email protected] module uses function constructor in two places:

1. https://github.com/stefanpenner/es6-promise/blob/f97e2666e6928745c450752e74213d2438b48b4c/lib/es6-promise/polyfill.js#L13
2. https://github.com/stefanpenner/es6-promise/blob/f97e2666e6928745c450752e74213d2438b48b4c/lib/es6-promise/asap.js#L99

i.e. to global object.
See https://developer.mozilla.org/en-US/docs/Glossary/Global_object

While we only need promise polyfill in IE11, this PR suggests replacing es6-promise module with native-promise-only module which listed second here and also reduces the bundle sizes.

@plotly/plotly_js

cc: #5395

[alexcjohnson]

If you've tested IE11 with an async plot (MathJax perhaps) and it works, then this is great! 💃

[nicolaskruchten]

From the readme of native-promise-only it's not clear to me if this supports IE11...?

[archmoj]

native-promise-only

It does support IE11.
Have you noticed any particular problem?

[nicolaskruchten]

No, I just read the documentation looking for a clear assertion of IE11 support and didn't find one, but if you're confident about your IE11 testing, this seems like a great solution :)