Prevent duplicate AttributeOptionGroup creation

[mfarhan943]

---

Fix: Prevent Duplicate AttributeOptionGroup Creation

Resolves: #372

Context

The options field in AttributeOptionGroupSerializer is defined using:

slug_field="option"

This means the serializer works with data like:

[
  {"option": "Large"},
  {"option": "Medium"}
]

However, when updating existing instances, the model receives options as actual AttributeOption instances:

[<AttributeOption: Large>, <AttributeOption: Medium>, <AttributeOption: Small>, <AttributeOption: Rokeol>]

This mismatch caused find_existing_attribute_option_group to fail at detecting duplicates — resulting in unnecessary creation of duplicate option groups even when the name and options were the same.

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What Changed

Updated find_existing_attribute_option_group to:

• Accept and normalize both:

  • {"option": "Large"}-style dicts from the serializer, and
  • AttributeOption instances from the model.

• Raise clear exceptions (ValueError, TypeError) for bad input.

---

• Prevents duplicate option groups when posting or updating with the same name/options.
• Supports both create and update flows.
• Validated by new tests for error handling and matching behavior.

---

[mfarhan943]

@samar-hassan Kindly review.

[samar-hassan]

please remove these trailing commas if its not new code

[mfarhan943]

Done.

[samar-hassan]

please add it again, lint fails

[mfarhan943]

Done.

[samar-hassan]

please rebase your branch