Remove `ServiceBuilderCommand` and implement the chain ops as standalone functions instead. (#6543)

* :)

* Slight tidy

* Remove ServiceBuilderCommand

* Remove whitespace

* Keep task manager alive for check_block/import_blocks

* Pass task_manager to run_until_exit

* Make task_manager in run_until_exit and make subcommands async

* Change the async_run fn to return a future and task manager

* async_run should take a result fn

* Apply suggestions from code review

Co-authored-by: Bastian Köcher <[email protected]>

* Fix spaces in export_raw_state

Co-authored-by: Bastian Köcher <[email protected]>