dra: add "named resources" structured parameter model

Like the current device plugin interface, a DRA driver using this model
announces a list of resource instances. In contrast to device plugins, this
list is made available to the scheduler together with attributes that can be
used to select suitable instances when they are not all alike.

Because this is the first structured parameter model, some checks that
previously were not possible, in particular "is one structured parameter field
set", now gets enabled. Adding another structured parameter model will be
similar.

The applyconfigs code generator assumes that all types in an API are defined in
a single package. If it wasn't for that, it would be possible to place the
"named resources" types in separate packages, which makes their names in the Go
code more natural and provides an indication of their stability level because
the package name could include a version.

pkg/apis/resource/validation/validation_noderesourceslice_test.go

@@ -32,10 +32,10 @@ func testNodeResourceSlice(name, nodeName, driverName string) *resource.NodeReso
 		ObjectMeta: metav1.ObjectMeta{
 			Name: name,
 		},
-		NodeName:          nodeName,
-		DriverName:        driverName,
+		NodeName:   nodeName,
+		DriverName: driverName,
 		NodeResourceModel: resource.NodeResourceModel{
-			// TODO: implement one structured parameter model
+			NamedResources: &resource.NamedResourcesResources{},
 		},
 	}
 }
@@ -188,15 +188,14 @@ func TestValidateNodeResourceSlice(t *testing.T) {
 			slice:        testNodeResourceSlice(goodName, goodName, badName),
 		},
 
-		// TODO: implement one structured parameter model
-		// "empty-model": {
-		// 	wantFailures: field.ErrorList{field.Required(nil, "exactly one structured model field must be set")},
-		// 	slice: func() *resource.NodeResourceSlice {
-		// 		slice := testNodeResourceSlice(goodName, goodName, driverName)
-		// 		slice.NodeResourceModel = resource.NodeResourceModel{}
-		// 		return slice
-		// 	}(),
-		// },
+		"empty-model": {
+			wantFailures: field.ErrorList{field.Required(nil, "exactly one structured model field must be set")},
+			slice: func() *resource.NodeResourceSlice {
+				slice := testNodeResourceSlice(goodName, goodName, driverName)
+				slice.NodeResourceModel = resource.NodeResourceModel{}
+				return slice
+			}(),
+		},
 	}
 
 	for name, scenario := range scenarios {