* chore: use type for rate limit config
Use type instead of `seq[string]` for rate limit config earlier.
Enables to fail faster (at config time) if the string is malformated
Also enables using object in some scenarios.
* test: remove import warnings
* improve naming and add tests
* fix: deprecate `--dns-discovery`
Properly deprecates `--dns-discovery` CLI arg.
DNS Discovery is enabled if a non-empty DNS Discovery URL is passed.
* test: add test_all for factory
add and use test_all for some tests.
