Sync devtools
Centralize exception message construction
Replace explicit Chain#each with Lupo.enumerable
Simplify Processor by using concord
Simplify Response by using concord
Simplify DSL::Registry using concord and lupo

Rename the internal collection state ivar to @items since
Enumerable#entries is already provided by ruby.
Simplify DSL::Guard using concord
Simplify Chain::Definition using lupo
Prefer or over || for control flow
Update flay and reek configs