Implement a function objectMap(obj, iteratee) that transforms the values of an object using the provided iteratee function.

The function should:

• Accept an object and an iteratee function.
• Apply the iteratee to each value in the object.
• Return a new object with the same keys and transformed values.
• Return an empty object if input is null or not an object.

Examples

objectMap({ a: 1, b: 2, c: 3 }, x => x * 2); 
// { a: 2, b: 4, c: 6 }

objectMap({ name: "Alice", age: 25 }, v => String(v));
// { name: "Alice", age: "25" }

objectMap({}, v => v);
// {}