preserve reentrant header used for actors ... through the service invocation process

In the dapr doc info, they show some reentrant actor scenarios. It looks like the dapr dotnet sdk automatically creates and passes the reentrant header id ... so as long as you follow the basic scenarios described in the docs it works fine.

```
ActorA -> ActorA
ActorA -> ActorB -> ActorA
```
https://docs.dapr.io/developing-applications/building-blocks/actors/actor-reentrancy/

I am wanting a do a slightly different scenario that includes a service invocation in the process.

```
ActorA -> invoke some service -> ActorA
```

This is currently not working because the reentrant header is not automatically preserved during a service invocation.