Long collection doesn't work serialize properly

We've introduced data collections [in rpc here](https://github.com/Azure/azure-functions-host/wiki/Out-of-Proc-Worker-Capabilities#typeddatacollection) for out of proc for things like `byte[][]` and `string[]`. There's a type for `long[]` and `double[]` too, but they aren't used it seems.

In .NET isolated process model, we see that double[] gets treated as a string list "[123.123123]" and deserializes ok, but long[] fails.