Port JS API to new Context API

[epilys]

All done.

Status: some bugs in Memory tests.

Also js-wasi tests are failing.

#2892

[epilys]

Ok so the blocking problem is here:

wasmer/lib/api/src/js/externals/function.rs

Lines 456 to 492 in 0943422

	pub fn call(
	&self,
	_ctx: &mut impl AsContextMut,
	_params: &[Value],
	) -> Result<Box<[Value]>, RuntimeError> {
	unimplemented!("Can't call functions with ContextMut as first parameter yet.");
	/*
	let arr = js_sys::Array::new_with_length(params.len() as u32);
	for (i, param) in params.iter().enumerate() {
	let js_value = param.as_jsvalue(&ctx.as_context_ref());
	arr.set(i as u32, js_value);
	}
	let result = js_sys::Reflect::apply(
	&self.handle.get(ctx.as_context_ref().objects()).function,
	&wasm_bindgen::JsValue::NULL,
	&arr,
	)?;
	let result_types = self.handle.get(ctx.as_context_ref().objects()).ty.results();
	match result_types.len() {
	0 => Ok(Box::new([])),
	1 => {
	let value = param_from_js(&result_types[0], &result);
	Ok(vec![value].into_boxed_slice())
	}
	_n => {
	let result_array: Array = result.into();
	Ok(result_array
	.iter()
	.enumerate()
	.map(|(i, js_val)| param_from_js(&result_types[i], &js_val))
	.collect::<Vec<_>>()
	.into_boxed_slice())
	}
	}
	*/
	}

When calling arbritary JS functions, we should put the context ContextMut<'_, _> as first argument of the js function. Doesn't that mean we have to expose it as a JS Object therefore JsValue with wasm-bindgen? Have I misunderstood how functions will be interacting with the context in general?

CC @Amanieu if you have the time to shed some light.