Moving a Post to a Collection should replicate API's behaviour

[AngeloStavrow]

The /api/collections/{COLLECTION_ALIAS}/move enpoint takes an array of post IDs as an argument and returns, in its response's data object, "an array of response envelopes: each with code and post (with full post data) on success, or code and error_msg on failure for any given post."

This is not the case for the WriteFreelyClient.movePost(postId: with modifyToken: to collectionAlias: completion:) method, which works with single post IDs and returns a Result<Bool, Error> in the completion handler.

This is classified a bug because it diverges from the behaviour of the API.