Ambiguous API models/dto/contracts

[bleepzter]

• There are several instances where API Models contain domain models when they shouldn't.
• No clear conversion between API models and domain models.
• Update function takes a ShortUrlEntity which inherits from TableEntity. Its hard to know what we need to send to the function without bringing in the storage SDK so that we can fill in the fields that are described by TableEntity.
• Create function returns a descriptor and not the actual etag ShortUrlEntity. If you want to update a ShortUrlEntity you have to first find it with the List function and then update it afterwards.