delete(key, path) sets value to 'undefined' instead of removing property

[BENx2115]

When using enmap.delete(key, path), the property at the given path is not actually deleted.
Instead, its value is replaced with undefined.

This causes the key to still exist in the object, which is unexpected behavior for a delete operation.

Example

enmap.set("user", {
  name: "Ben",
  age: 25
});

enmap.delete("user", "age");

console.log(enmap.get("user"));

Current Result

{
  name: "Ben",
  age: undefined
}

Expected Result

{
  name: "Ben"
}

• Enmap version: 6.1.6

[miichom]

Within JavaScript, this is intended behaviour. It was declared before but now its not initialised/no value assigned. The PR #147 would hope to produce the correct typings for this.