This change adds a new `dns_config.recursor_strategy` option which
controls how Consul queries DNS resolvers listed in the `recursors`
config option. The supported options are `sequential` (default), and
`random`.
Closes#8807
Co-authored-by: Blake Covarrubias <blake@covarrubi.as>
Co-authored-by: Priyanka Sengupta <psengupta@flatiron.com>