feat: allow lists in the dict values of the hooks argument

[label-hook]

Summary

This PR enhances the Request class to accept lists of hook functions in the hooks parameter, addressing a limitation where only single hook functions could be specified per hook type. Previously, passing a list would cause the code to wrap it in another list, making it non-callable and causing failures.

Changes

• Modified Request.__init__() in requests/models.py to properly handle lists as values in the hooks parameter
• Added logic to detect when a hook value is already a list/iterable of callables and use it directly instead of wrapping it
• Maintained backward compatibility with single callable hooks
• Improved hook processing to handle edge cases like empty lists and mixed types

Testing

The changes were verified through comprehensive testing:

• Single hook functions continue to work as before (backward compatibility)
• Lists of hook functions are properly registered and executed
• Mixed scenarios with both single functions and lists work correctly
• Integration with Session hooks functions properly
• Edge cases like empty lists are handled gracefully

The baseline test suite was already failing before these changes, and no new test failures were introduced by this implementation.

Closes #116

---

Closes #116