Suport Spring ParameterizedTypeReference for returnTypes of Workflow CallActivity()

## Expected Behavior

When calling a Workflow activity, we should support parameterized types for return types, as it is supported in Spring:

```
new ParameterizedTypeReference>(){}
```

## Actual Behavior

We only support Class returnType;

```
default Task callActivity(String name, Object input, Class returnType)
```

## Steps to Reproduce the Problem

## Release Note

RELEASE NOTE: