[Enhancement] disallow writing into node_modules folder by scripts

Unexperienced users seem to wirte i.e. into node_modules/iobroker.javascript.

See https://forum.iobroker.net/topic/83890/mit-exec-in-dateisystem-schreiben

If possible this operation should be blocked or at least cause an error. User files dynamically created be scripts must not be stored within the official source directory of the adapter. 