Introspection throughput calculation with building blocks

## Brief feature description

Introspection throughput calculation must be adapted to work with building blocks. In adidtion, the throughput calculation should have less impact on the system as it used to.

## Detailed information

Add introspection throughput calculation with building blocks. However, we don't want pay for throughput calculation in every publisher just because somebody could be interested.

For example:
- In ROS you can do it with the tools by doing something like ros2 topic /myTopic bw. If a gateway needs this information the job would be there. For the introspection it would be easy to have this as an extra functionality, maybe also per topic and maybe as separate application?
- Should we start throughput calc only when the introspection is started/registered at RouDi? This could apply to all introspection related data (mempool info etc.)