Only done outcome in Studio if subclassing FlowSendHttpRequest

## Description
If I create a subclass of FlowSendHttpRequest (like MyFlowSendHttpRequest) then the only outcome shown in Studio is "Done". No outcome/port for expected status code, tiomeout etc as with the original FlowSendHttpRequest. Not even if you duplicate the entire class.

## Steps to Reproduce
Create a subclass of FlowSendHttpRequest activity (inherit from FlowSendHttpRequest). Run Studio and add the custom activity to workflow. Only Done outcome.

## Expected Behavior
Should have same outcomes / portsvisible as FlowSendHttpRequest

## Actual Behavior
Only "Done" outcome.

## Environment
- **Elsa Package Version**: Elsa 3.5.3
- **Operating System**: Windows 10

## Troubleshooting Attempts
- Using FlowNodeAttribute. Seems to work but then you have no dynmaic outcome depending on status code.
- Tried to duplicate everythign in FlowSendHttpRequest (and inherit from base class just like FlowSendHttpRequest). Same.