feat: Delegated routing with custom configuration. (#9274)

New multi-router configuration system based on https://hackmd.io/G1KRDEX5T3qyfoBMkIrBew#Methods

- Added a new routing type: "custom"
- Added specific struct types for different Routers (instead of map[string]interface{})
- Added `Duration` config type, to make easier time string parsing
- Added config documentation.
- Use the latest go-delegated-routing library version with GET support.
- Added changelog notes for this feature.

It:
- closes #9157
- closes #9079
- closes #9186

cmd/ipfs/daemon.go

@@ -59,6 +59,7 @@ const (
 	routingOptionDHTKwd       = "dht"
 	routingOptionDHTServerKwd = "dhtserver"
 	routingOptionNoneKwd      = "none"
+	routingOptionCustomKwd    = "custom"
 	routingOptionDefaultKwd   = "default"
 	unencryptTransportKwd     = "disable-transport-encryption"
 	unrestrictedApiAccessKwd  = "unrestricted-api"
@@ -401,7 +402,10 @@ func daemonFunc(req *cmds.Request, re cmds.ResponseEmitter, env cmds.Environment
 
 	routingOption, _ := req.Options[routingOptionKwd].(string)
 	if routingOption == routingOptionDefaultKwd {
-		routingOption = cfg.Routing.Type.WithDefault(routingOptionDHTKwd)
+		routingOption = cfg.Routing.Type
+		if routingOption == "" {
+			routingOption = routingOptionDHTKwd
+		}
 	}
 	switch routingOption {
 	case routingOptionSupernodeKwd:
@@ -414,6 +418,14 @@ func daemonFunc(req *cmds.Request, re cmds.ResponseEmitter, env cmds.Environment
 		ncfg.Routing = libp2p.DHTServerOption
 	case routingOptionNoneKwd:
 		ncfg.Routing = libp2p.NilRouterOption
+	case routingOptionCustomKwd:
+		ncfg.Routing = libp2p.ConstructDelegatedRouting(
+			cfg.Routing.Routers,
+			cfg.Routing.Methods,
+			cfg.Identity.PeerID,
+			cfg.Addresses.Swarm,
+			cfg.Identity.PrivKey,
+		)
 	default:
 		return fmt.Errorf("unrecognized routing option: %s", routingOption)
 	}