JsLIGO Remove Parser Requirement for Mandatory Parameter Annotations

type:changed

Related to #1456 (closed) and #1452. Removes parser requirement that JsLIGO function parameters have a mandatory annotation.

For example, we can now write functions without annotations (allowing complete type inference)

let for_of_single_statement = xs => {
    let ys = list([]);
    for (const x of xs) {
        ys = list([x, ...ys]);
    };
    return ys;
}

Changelog details: Remove requirement that JsLIGO function parameters must be annotated