* feat(medusa): Add /admin/products/:id/variants end point
* test(medusa): Fix get-variants test casees
* feat(medusa): Include the config to the ProdutService#retrieveVariants as a method parameter
* feat(medusa): Improve get-variants endpoint
* feat(medusa): Improve get-variants endpoint
* test(medusa): Fix unit tests
* test(medusa): Fix unit tests
* feat(medusa): Improve typings
* feat(medusa): Update according to feedback
* feat(medusa): Update according to feedback
* test(medusa): Fix list-variants tests
* feat(medusa): Getting the variants from the product end point should use the productVariantService
* fix(medusa): list-variants expand possibly undefined
* Fix(medusa): List-variants endpoint
* fix(medusa): Tests suite for list-variant
* test(integration-tests): Fix yarn lock
* test(integration-tests): Fix yarn lock