Make `id` field required for CosmosDB v4 output binding

In v3.x of the CosmosDB extension, an `id` field was _not_ required for CosmosDB output bindings, as an autogenerated GUID was assigned if no `id` was explicitly specified. One less documented change in v4.x is that now an `id` field _is_ required, and an ID field is no longer automatically generated if none is specified. This is related to a [similar change](https://learn.microsoft.com/en-US/azure/cosmos-db/nosql/migrate-dotnet-v3?tabs=dotnet-v3#changes-to-item-id-generation) on the underlying SDK. We recently had [a CRI](https://portal.microsofticm.com/imp/v3/incidents/incident/423070700/summary) where a customer (using a node app) was confused about this new behavior, especially since it is not well documented. We can help mitigate future confusion by making an `id` field required when setting a CosmosDB v4 output binding.