Add v2 version to go module name

Replace all elements from `v2` to root directory.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>

tombstone/grpc/types.go

@@ -0,0 +1,26 @@
+package tombstone
+
+import (
+	refs "github.com/nspcc-dev/neofs-api-go/v2/refs/grpc"
+)
+
+// SetExpirationEpoch sets number of tombstone expiration epoch.
+func (x *Tombstone) SetExpirationEpoch(v uint64) {
+	if x != nil {
+		x.ExpirationEpoch = v
+	}
+}
+
+// SetSplitId sets identifier of split object hierarchy.
+func (x *Tombstone) SetSplitId(v []byte) {
+	if x != nil {
+		x.SplitId = v
+	}
+}
+
+// SetMembers sets list of objects to be deleted.
+func (x *Tombstone) SetMembers(v []*refs.ObjectID) {
+	if x != nil {
+		x.Members = v
+	}
+}