[JS IR] Re-export all JS-exports from main module in multi-module mode

Add an implicit transitive re-export through
main module for all other module's JS-exports.

js/js.translator/testData/box/multiModule/exportFromModules.js

@@ -0,0 +1,18 @@
+$kotlin_test_internal$.beginModule();
+
+module.exports = function() {
+    var demoPackage = require("main").demoPackage
+
+    var a1 = demoPackage.a1.ModuleA1Class
+    var a2 = demoPackage.a2.moduleA2Function
+    var bb = demoPackage.b.moduleBFunction
+
+    return {
+     "moduleA1": (new a1()).toString(),
+     "moduleA2": a2().toString(),
+     "moduleB": bb()
+    };
+};
+
+$kotlin_test_internal$.endModule("lib");
+