Move JS client to generator functions

[oscartbeaumont]

If this is even possible it should hopefully reduce bundle size a bit and would be easier to understand than the custom Oberservable implementation.

[ken0x0a]

TypeScript doesn't work well with generators...

[oscartbeaumont]

Interesting. I don't have much experience but they look alright just doing some quick tests.

They are more of an implement detail anyway, most people won't touch the link API (and generally if they do they have to do typecasting anyway).