Lighthouse bootnode (#1265)

* Initial bootnode structure

* Add boot_node subcommand

* Add bootnode subcommand

* fmt corrections

* Extend help message

* Move boot_node crate

* Update discv5 dep

* Improve logging and boot-node logging

Co-authored-by: Paul Hauner <paul@paulhauner.com>

Cargo.toml

@@ -1,6 +1,7 @@
 [workspace]
 members = [
     "account_manager",
+
     "beacon_node",
     "beacon_node/beacon_chain",
     "beacon_node/client",
@@ -13,6 +14,8 @@ members = [
     "beacon_node/version",
     "beacon_node/websocket_server",
 
+	"boot_node",
+
     "common/clap_utils",
     "common/compare_fields",
     "common/compare_fields_derive",