stacks: add deferred to grpc calls

internal/plugin/grpc_provider.go

@@ -622,6 +622,9 @@ func (p *GRPCProvider) ImportResourceState(r providers.ImportResourceStateReques
 	protoReq := &proto.ImportResourceState_Request{
 		TypeName: r.TypeName,
 		Id:       r.ID,
+		ClientCapabilities: &proto.ClientCapabilities{
+			DeferralAllowed: r.ClientCapabilities.DeferralAllowed,
+		},
 	}
 
 	protoResp, err := p.client.ImportResourceState(p.ctx, protoReq)
@@ -630,6 +633,7 @@ func (p *GRPCProvider) ImportResourceState(r providers.ImportResourceStateReques
 		return resp
 	}
 	resp.Diagnostics = resp.Diagnostics.Append(convert.ProtoToDiagnostics(protoResp.Diagnostics))
+	resp.Deferred = convert.ProtoToDeferred(protoResp.Deferred)
 
 	for _, imported := range protoResp.ImportedResources {
 		resource := providers.ImportedResource{

internal/plugin6/grpc_provider.go

@@ -611,6 +611,9 @@ func (p *GRPCProvider) ImportResourceState(r providers.ImportResourceStateReques
 	protoReq := &proto6.ImportResourceState_Request{
 		TypeName: r.TypeName,
 		Id:       r.ID,
+		ClientCapabilities: &proto6.ClientCapabilities{
+			DeferralAllowed: r.ClientCapabilities.DeferralAllowed,
+		},
 	}
 
 	protoResp, err := p.client.ImportResourceState(p.ctx, protoReq)
@@ -619,6 +622,7 @@ func (p *GRPCProvider) ImportResourceState(r providers.ImportResourceStateReques
 		return resp
 	}
 	resp.Diagnostics = resp.Diagnostics.Append(convert.ProtoToDiagnostics(protoResp.Diagnostics))
+	resp.Deferred = convert.ProtoToDeferred(protoResp.Deferred)
 
 	for _, imported := range protoResp.ImportedResources {
 		resource := providers.ImportedResource{

internal/providers/provider.go

@@ -425,6 +425,9 @@ type ImportResourceStateRequest struct {
 	// ID is a string with which the provider can identify the resource to be
 	// imported.
 	ID string
+
+	// ClientCapabilities contains information about the client's capabilities.
+	ClientCapabilities ClientCapabilities
 }
 
 type ImportResourceStateResponse struct {
@@ -436,6 +439,10 @@ type ImportResourceStateResponse struct {
 
 	// Diagnostics contains any warnings or errors from the method call.
 	Diagnostics tfdiags.Diagnostics
+
+	// Deferred if present signals that the provider was not able to fully
+	// complete this operation and a susequent run is required.
+	Deferred *Deferred
 }
 
 // ImportedResource represents an object being imported into Terraform with the