Initial Store & Forward Implementation (#2917)

This adds store & forward relays into dendrite for p2p.
A few things have changed:
- new relay api serves new http endpoints for s&f federation
- updated outbound federation queueing which will attempt to forward
using s&f if appropriate
- database entries to track s&f relays for other nodes

setup/monolith.go

@@ -23,6 +23,8 @@ import (
 	"github.com/matrix-org/dendrite/internal/transactions"
 	keyAPI "github.com/matrix-org/dendrite/keyserver/api"
 	"github.com/matrix-org/dendrite/mediaapi"
+	"github.com/matrix-org/dendrite/relayapi"
+	relayAPI "github.com/matrix-org/dendrite/relayapi/api"
 	roomserverAPI "github.com/matrix-org/dendrite/roomserver/api"
 	"github.com/matrix-org/dendrite/setup/base"
 	"github.com/matrix-org/dendrite/setup/config"
@@ -44,6 +46,7 @@ type Monolith struct {
 	RoomserverAPI roomserverAPI.RoomserverInternalAPI
 	UserAPI       userapi.UserInternalAPI
 	KeyAPI        keyAPI.KeyInternalAPI
+	RelayAPI      relayAPI.RelayInternalAPI
 
 	// Optional
 	ExtPublicRoomsProvider   api.ExtraPublicRoomsProvider
@@ -71,4 +74,8 @@ func (m *Monolith) AddAllPublicRoutes(base *base.BaseDendrite) {
 	syncapi.AddPublicRoutes(
 		base, m.UserAPI, m.RoomserverAPI, m.KeyAPI,
 	)
+
+	if m.RelayAPI != nil {
+		relayapi.AddPublicRoutes(base, m.KeyRing, m.RelayAPI)
+	}
 }