Enhancement: String Concatenation with Null Values Should Not Yield Null

[MisterGC]

Concatenating a string with null results in null, e.g., 'value: ' + root.node.value becomes null if root.node.value is null. Although explicit conversion to string is supported it is not very convinient and the pure null result in the case of forgetting it is confusing.

Suggested Improvement:
Change the behavior so that concatenating with null converts null to the string "null", leading to results like "value: null" instead of null. This change would improve clarity and utility in outputs, especially useful in scenarios involving data display and debugging.

Example:

// Current output: null
// Desired output: "value: null"