mesh: add ComputedImplicitDestinations resource for future use

Also:

- Add some v2 TestController machinery to help test complex
  dependency mappers.

proto-public/pbauth/v2beta1/traffic_permissions.go

@@ -0,0 +1,19 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package authv2beta1
+
+import (
+	pbresource "github.com/hashicorp/consul/proto-public/pbresource"
+)
+
+func (src *Source) GetWorkloadIdentityReference() *pbresource.Reference {
+	return &pbresource.Reference{
+		Type: WorkloadIdentityType,
+		Name: src.IdentityName,
+		Tenancy: &pbresource.Tenancy{
+			Partition: src.Partition,
+			Namespace: src.Namespace,
+		},
+	}
+}

proto-public/pbmesh/v2beta1/resources.rtypes.go

@@ -20,6 +20,7 @@ const (
 	DestinationsConfigurationKind    = "DestinationsConfiguration"
 	GRPCRouteKind                    = "GRPCRoute"
 	HTTPRouteKind                    = "HTTPRoute"
+	ImplicitDestinationKind          = "ImplicitDestination"
 	MeshConfigurationKind            = "MeshConfiguration"
 	MeshGatewayKind                  = "MeshGateway"
 	ProxyConfigurationKind           = "ProxyConfiguration"
@@ -88,6 +89,12 @@ var (
 		Kind:         HTTPRouteKind,
 	}
 
+	ImplicitDestinationType = &pbresource.Type{
+		Group:        GroupName,
+		GroupVersion: Version,
+		Kind:         ImplicitDestinationKind,
+	}
+
 	MeshConfigurationType = &pbresource.Type{
 		Group:        GroupName,
 		GroupVersion: Version,