Add support for enableMetadataWithRecommendations for recommenders and campaigns

[james-jory]

Describe the feature you'd like
Personalize recently added support for returning item metadata with responses from Recommenders and Campaigns. However, this capability is not allowed with this solution.

https://docs.aws.amazon.com/personalize/latest/dg/creating-recommenders.html#create-recommender-return-metadata
https://docs.aws.amazon.com/personalize/latest/dg/campaigns.html#create-campaign-return-metadata

[fhoueto-amz]

Hi James
Thanks for your suggestion. We will review.
Fabien