Follow up to 6f8f6a7726
Prior to the linked commit, the `uploads#create` endpoint had a `upload_type` and `type` param that acted as aliases for each other and raised an error if both of them were missing. In the linked commit, we removed the `type` param and always required the `upload_type` param which break API consumers that only included `type` in their requests.
This commit adds back the `type` param temporarily and introduces a deprecation message for it so that API consumers are made aware of the eventual removal of the `type` param.