Improve product rest api error responses for publisher

[tharikaGitHub]

This PR adds improvements to the following Publisher product rest api error responses.

1. /apis/import-openapi - POST
2. /apis/change-lifecycle - POST
3. /apis/{apiId}/revisions - POST
4. /apis/{apiId}/deploy-revision - POST
5. /apis/{apiId}/undeploy-revision - POST
6. /apis/import - POST
7. /api-products/{apiProductId}/revisions - POST
8. /api-products/{apiProductId}/deploy-revision - POST
9. /api-products/{apiProductId}/undeploy-revision - POST
10. /api-products/change-lifecycle - POST
11. /api-products/import - POST
12. /api-products - POST
13. /api-products/{apiProductId} - PUT
14. /apis/copy-api - POST
15. /apis/{apiId}/swagger - PUT

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[tharikaGitHub]

The test failures are addressed through wso2/product-apim#13535