- Adding `equals` and `hashCode` methods for proper object comparison.
- Implementing a deep `copy()` method, creating new instances of mutable collections (List, Set, Map, Metadata) to prevent shared state.
- Adding `AzureOpenAiChatOptionsTests` to verify `copy()`, builders, setters, and default values.
Signed-off-by: Alexandros Pappas <apappascs@gmail.com>