Normative: Arbitrary module namespace identifier names

[bmeck]

I do not believe this affects any integration downstream.

This PR aims to allow:

import {"\0 any unicode" as foo} from "";
export {foo as "\0 any unicode"};

This matches the restriction that WASM has that the string names for exports must be valid Unicode.

Depends on #2155

[devsnek]

InitializeBoundName only accepts strings

[bmeck]

Updated, now depends on #2155

[JLHwung]

Should we allow { ModuleExportName as ModuleExportName } in ExportFromtClause?

The goal example

import {"\0 any unicode" as foo} from "";
export {foo as "\0 any unicode"};

reminds me of the following one-liner:

export {"\0 any unicode" as "\0 any unicode"} from "some-module";

[ExE-Boss]

It should also be possible to do:

export { "\0 any unicode" } from "some-module";