Generic Linked List with void*

Implement a generic linked list using void* to store any data type.

Requirements:

• Define Node struct with void* data and next pointer
• Implement create_node, prepend, append, find, free_list
• Must work with int, float, and custom structs
• Use malloc to copy data into nodes (don't store pointers directly)
• Clean memory management (free all allocated memory)
• Provide compare function for find operation