Separate accounts/host catalogs/host sets into their own packages (#311)

internal/proto/local/controller/api/resources/hostsets/v1/host_set.proto

@@ -0,0 +1,57 @@
+syntax = "proto3";
+
+package controller.api.resources.hostsets.v1;
+
+option go_package = "github.com/hashicorp/boundary/internal/gen/controller/api/resources/hostsets;hostsets";
+
+import "google/protobuf/struct.proto";
+import "google/protobuf/timestamp.proto";
+import "google/protobuf/wrappers.proto";
+import "controller/api/resources/hosts/v1/host.proto";
+import "controller/api/resources/scopes/v1/scope.proto";
+import "controller/custom_options/v1/options.proto";
+
+// HostSet is a collection of Hosts created and managed by a HostCatalog
+message HostSet {
+	// The ID of the host
+	// Output only.
+	string id = 10;
+
+	// Scope information for this resource
+	// Output only.
+	resources.scopes.v1.ScopeInfo scope = 20;
+
+	// Optional name for identification purposes
+	google.protobuf.StringValue name = 30 [(custom_options.v1.generate_sdk_option) = true, (custom_options.v1.mask_mapping) = {this:"name" that: "name"}];
+
+	// Optional user-set description for identification purposes
+	google.protobuf.StringValue description = 40 [(custom_options.v1.generate_sdk_option) = true, (custom_options.v1.mask_mapping) = {this:"description" that: "description"}];
+
+	// The time this resource was created
+	// Output only.
+	google.protobuf.Timestamp created_time = 50 [json_name="created_time"];
+
+	// The time this resource was last updated
+	// Output only.
+	google.protobuf.Timestamp updated_time = 60 [json_name="updated_time"];
+
+	// The version can be used in subsequent write requests to ensure this resource
+	// has not changed and to fail the write if it has.
+	uint32 version = 70;
+
+	// The type of the resource, to help differentiate schemas
+	string type = 80;
+
+	// The host catalog this host set is a part of
+	// Output only
+	string host_catalog_id = 90 [json_name="host_catalog_id"];
+
+	// A list of hosts in this host set
+	// TODO: Figure out if this should be in the basic HostSet view and what
+	// view to use on the Hosts.
+	// Output only.
+	repeated string host_ids = 100;
+
+	// The attributes that are applied for the specific host set type.
+	google.protobuf.Struct attributes = 110;
+}