feat(multistore): extract multistore code to repo

Extract multistore + multiread blockstore to a seperate repo

node/modules/client.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"time"
 
+	"github.com/filecoin-project/go-multistore"
 	"github.com/filecoin-project/lotus/lib/bufbstore"
 	"golang.org/x/xerrors"
 
@@ -42,7 +43,7 @@ func ClientMultiDatastore(lc fx.Lifecycle, r repo.LockedRepo) (dtypes.ClientMult
 		return nil, xerrors.Errorf("getting datastore out of reop: %w", err)
 	}
 
-	mds, err := importmgr.NewMultiDstore(ds)
+	mds, err := multistore.NewMultiDstore(ds)
 	if err != nil {
 		return nil, err
 	}

node/modules/dtypes/storage.go

@@ -9,6 +9,7 @@ import (
 	format "github.com/ipfs/go-ipld-format"
 
 	"github.com/filecoin-project/go-fil-markets/storagemarket/impl/requestvalidation"
+	"github.com/filecoin-project/go-multistore"
 
 	datatransfer "github.com/filecoin-project/go-data-transfer"
 	"github.com/filecoin-project/go-fil-markets/piecestore"
@@ -27,7 +28,7 @@ type ChainGCBlockstore blockstore.GCBlockstore
 type ChainExchange exchange.Interface
 type ChainBlockService bserv.BlockService
 
-type ClientMultiDstore *importmgr.MultiStore
+type ClientMultiDstore *multistore.MultiStore
 type ClientImportMgr *importmgr.Mgr
 type ClientBlockstore blockstore.Blockstore
 type ClientDealStore *statestore.StateStore