fix(medusa): Assign metadata when creating a draft order or creating a line item (#4662)

When creating a draft order or creating a line item via Postman, filled metadata is not saved, metadata remains null in the API response

Co-authored-by: Oli Juhl <59018053+olivermrbl@users.noreply.github.com>

.changeset/angry-ways-sell.md

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+---
+"@medusajs/medusa": patch
+---
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+fix(medusa): Assign metadata when creating a draft order or creating a line item