Add option to exclude suspended domains/subdomains from tootctl domains crawl (#11454)

* Add "--exclude-suspended" to tootctl domains crawl

This new option ignores any instances suspended server-wide as
well as their associated subdomains. This queries all domain
blocks up front, then runs a regexp on each domain. This improves
performance over what may be the obvious implementation, which is
to ask `DomainBlocks.blocked?(domain)` for each domain -- this
hits the DB many times, slowing things down considerably.

* cleaning up code style

* Compiling regex

* Removing ternary operator