fix: Allow union of destinations in fulfillment tests

[semenovm]

Description

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include relevant motivation and context.

Type of change

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• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing
  functionality to not work as expected, including removal of schema files
  or fields)
• Documentation update

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Checklist

• My code follows the style guidelines of this project
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According to documentation, business should return: Available destinations. For shipping: addresses. For pickup: retail locations.

There is no mention in the documentation that after updating destination by a platform, only selected destination should be returned. It also doesn't fit pickup scenario (user doesn't know store locations).

This change relaxes the check to verify destinations include new destination.

Ideally it should compare lists before and after but then python implementation will fail the test (lets update it first before making the test strict).