Support streaming for binding requests

[akkie]

Describe the feature

In #560 a new way was introduced to call bindings with raw data. It would be good to also have a method to directly provide a stream, because when working with files, the raw data method always loads the files into memory, which can lead to memory issues when working with a lot of files.

Release Note

RELEASE NOTE: ADD Support streaming for binding requests

[WhitWaldo]

I would encourage you to open a request in https://github.com/dapr/dapr for this.

We could certainly add a method on the SDK for implementing this, but you'd simply get the entirety of the data filled at once by the runtime because the binding itself (managed by the runtime) doesn't stream. At best, there'd be no point today and at worst, it'd be misleading to SDK consumers by suggesting that the functionality is available even if it doesn't practically have any of the streaming benefits.

To get such support, the runtime would have to support streaming (I've been making the case for making this the default going forward) at which point the SDK can meet in the middle. Once the runtime has such support, I would certainly be amenable to adding it to the SDK.