Unify MethodCall and ReplayResults into SimulationResult

- Call and Replay now return the same type, which includes both Message and MessageReceipt

node/impl/full/state.go

@@ -143,14 +143,14 @@ func (a *StateAPI) StatePledgeCollateral(ctx context.Context, tsk types.TipSetKe
 		return types.NewInt(0), xerrors.Errorf("failed to get miner worker addr: %w", err)
 	}
 
-	if ret.ExitCode != 0 {
-		return types.NewInt(0), xerrors.Errorf("failed to get miner worker addr (exit code %d)", ret.ExitCode)
+	if ret.MsgRct.ExitCode != 0 {
+		return types.NewInt(0), xerrors.Errorf("failed to get miner worker addr (exit code %d)", ret.MsgRct.ExitCode)
 	}
 
-	return types.BigFromBytes(ret.Return), nil
+	return types.BigFromBytes(ret.MsgRct.Return), nil
 }
 
-func (a *StateAPI) StateCall(ctx context.Context, msg *types.Message, tsk types.TipSetKey) (*api.MethodCall, error) {
+func (a *StateAPI) StateCall(ctx context.Context, msg *types.Message, tsk types.TipSetKey) (*api.InvocResult, error) {
 	ts, err := a.Chain.GetTipSetFromKey(tsk)
 	if err != nil {
 		return nil, xerrors.Errorf("loading tipset %s: %w", tsk, err)
@@ -158,7 +158,7 @@ func (a *StateAPI) StateCall(ctx context.Context, msg *types.Message, tsk types.
 	return a.StateManager.Call(ctx, msg, ts)
 }
 
-func (a *StateAPI) StateReplay(ctx context.Context, tsk types.TipSetKey, mc cid.Cid) (*api.ReplayResults, error) {
+func (a *StateAPI) StateReplay(ctx context.Context, tsk types.TipSetKey, mc cid.Cid) (*api.InvocResult, error) {
 	ts, err := a.Chain.GetTipSetFromKey(tsk)
 	if err != nil {
 		return nil, xerrors.Errorf("loading tipset %s: %w", tsk, err)
@@ -173,10 +173,10 @@ func (a *StateAPI) StateReplay(ctx context.Context, tsk types.TipSetKey, mc cid.
 		errstr = r.ActorErr.Error()
 	}
 
-	return &api.ReplayResults{
-		Msg:     m,
-		Receipt: &r.MessageReceipt,
-		Error:   errstr,
+	return &api.InvocResult{
+		Msg:    m,
+		MsgRct: &r.MessageReceipt,
+		Error:	errstr,
 	}, nil
 }