Throw meaningful error stubbing ECMAScript Module

Ref #1711 and #1623 for background.

This feature is simply about throwing a meaningful error, instead
one that tells the user that the property cannot be deleted. As
the exports from ECMAScript modules are immutable once created we
cannot do anything about them from the view of Sinon, so it's
preferable to simply tell the user that when we can.

This should not affect transpiled code (say, using Babel), as the
resulting modules are no longer true ECMAScript modules (but rather
some form of CommonJS module).

lib/sinon/stub.js

@@ -18,6 +18,14 @@ function stub(object, property) {
         throw new TypeError("stub(obj, 'meth', fn) has been removed, see documentation");
     }
 
+    if (
+        object &&
+        typeof Symbol !== "undefined" &&
+        object[Symbol.toStringTag] === "Module"
+    ) {
+        throw new TypeError("No support for stubbing ES Modules");
+    }
+
     throwOnFalsyObject.apply(null, arguments);
 
     if (object && typeof property !== "undefined" && !(property in object)) {