"JsRuntime::load_main_es_module_from_code" is broken

[bartlomieju]

After calling "JsRuntime::load_main_es_module_from_code" the loader tries to load the already provided module. This is problematic because it misses the point of this method in that we explicitly provide the code.

We either need to store it on the loader and alter the path to not try to load the root module anymore.