Preparations for removing BaseDendrite (#3016)

Preparations to actually remove/replace `BaseDendrite`.
Quite a few changes:
- SyncAPI accepts an `fulltext.Indexer` interface (fulltext is removed
from `BaseDendrite`)
- Caches are removed from `BaseDendrite`
- Introduces a `Router` struct (likely to change)
  - also fixes #2903
- Introduces a `sqlutil.ConnectionManager`, which should remove
`base.DatabaseConnection` later on
- probably more

clientapi/routing/login_test.go

@@ -9,6 +9,7 @@ import (
 	"testing"
 
 	"github.com/matrix-org/dendrite/clientapi/auth/authtypes"
+	"github.com/matrix-org/dendrite/internal/caching"
 	"github.com/matrix-org/dendrite/roomserver"
 	"github.com/matrix-org/dendrite/setup/config"
 	"github.com/matrix-org/gomatrixserverlib"
@@ -36,7 +37,8 @@ func TestLogin(t *testing.T) {
 			SigningIdentity: gomatrixserverlib.SigningIdentity{ServerName: "vh1"},
 		})
 
-		rsAPI := roomserver.NewInternalAPI(base)
+		caches := caching.NewRistrettoCache(base.Cfg.Global.Cache.EstimatedMaxSize, base.Cfg.Global.Cache.MaxAge, caching.DisableMetrics)
+		rsAPI := roomserver.NewInternalAPI(base, caches)
 		// Needed for /login
 		userAPI := userapi.NewInternalAPI(base, rsAPI, nil)
 
@@ -114,7 +116,7 @@ func TestLogin(t *testing.T) {
 					"password": password,
 				}))
 				rec := httptest.NewRecorder()
-				base.PublicClientAPIMux.ServeHTTP(rec, req)
+				base.Routers.Client.ServeHTTP(rec, req)
 				if tc.wantOK && rec.Code != http.StatusOK {
 					t.Fatalf("failed to login: %s", rec.Body.String())
 				}