Moves the setup request execution to run_fsm

[anarthal]

Adds unit tests to cover setup request execution in run_fsm
Entails no functional change

[anarthal]

This moves the setup request execution to the sans-io world. It uses an approach similar to the one I used for PINGs in the flexible health-checker.

This

• Simplifies the parallel group handling a lot, because we no longer have a task that finishes before the others.
• Moves more functionality to .ipps. Concretely, after merging this and Makes health checks flexible so they don't tear down connections under heavy load #328, all logging happens in ipp files. This will allow us to remove the connection_logger class completely, separating all logging functionality into the FSM ipp files.