We have a very subtle behavior change between python and js as split is quite different between two languages.
I don't think it is allowed to have a key with more than one `.`, but in case we do or mistyped an additional one,
we may silently ignore it and end up with hard-to-explain behavior.
With python code, if we had `dialer.nam.e = foo`, we ended up with `{entry_points:{dialer:{"nam.e":foo"}}`
With JS code we would now end up with `{entry_points:{dialer:{nam:"foo"}}`
That's because in python "a.b.c".split(".", 1) = ["a", "b.c"]
whereas in JS, "a.b.c".split(".", 2) = ["a", "b"]

We should throw an explicit error or prevent triming key part silently.