Leave `tootctl accounts cull` to simply check removed accounts from
live domains, and skip temporarily unavailable domains, while listing
them in the final output for further action.
Add `tootctl domains purge DOMAIN` to be able to purge a domain from
that list manually
* Move more tasks to tootctl
- tootctl feeds build
- tootctl feeds clear
- tootctl accounts refresh
Clean up exit codes and help messages
* Move user modifying to tootctl
* Improve user modification through CLI, rename commands
add -> create
mod -> modify
del -> delete
To remove ambiguity
* Fix code style issues
* Fix not being able to unset admin/mod role
