fix: handle require calls that are side effect only

[rturnq]

Currently require calls for side effects only (eg. where exports are not used) get converted to a namespace import which fails when the imported module has no exports.

require("foo");

will become something like

import * as __CJS__import__1__ from "foo";

which will error when foo has no exports.

This PR adds support for require calls that are for side effects only by checking if the parent AST node of the require CallExpression is an ExpressionStatement and replacing that entire node with the side-effect import.

require("foo");

will become

import "foo";