DRA: new API for 1.31

This is a complete revamp of the original API. Some of the key
differences:
- refocused on structured parameters and allocating devices
- support for constraints across devices
- support for allocating "all" or a fixed amount
  of similar devices in a single request
- no class for ResourceClaims, instead individual
  device requests are associated with a mandatory
  DeviceClass

For the sake of simplicity, optional basic types (ints, strings) where the null
value is the default are represented as values in the API types. This makes Go
code simpler because it doesn't have to check for nil (consumers) and values
can be set directly (producers). The effect is that in protobuf, these fields
always get encoded because `opt` only has an effect for pointers.

The roundtrip test data for v1.29.0 and v1.30.0 changes because of the new
"request" field. This is considered acceptable because the entire `claims`
field in the pod spec is still alpha.

The implementation is complete enough to bring up the apiserver.
Adapting other components follows.

Kubernetes-commit: 91d7882e867da25ae8014f679db32b20e35e89b4

Author: pohly

core/v1/generated.pb.go

@@ -2665,6 +2665,13 @@ type ResourceClaim struct {
 	// the Pod where this field is used. It makes that resource available
 	// inside a container.
 	Name string `json:"name" protobuf:"bytes,1,opt,name=name"`
+
+	// Request is the name chosen for a request in the referenced claim.
+	// If empty, everything from the claim is made available, otherwise
+	// only the result of this request.
+	//
+	// +optional
+	Request string `json:"request,omitempty" protobuf:"bytes,2,opt,name=request"`
 }
 
 const (

core/v1/generated.proto

@@ -2103,8 +2103,9 @@ func (ReplicationControllerStatus) SwaggerDoc() map[string]string {
 }
 
 var map_ResourceClaim = map[string]string{
-	"":     "ResourceClaim references one entry in PodSpec.ResourceClaims.",
-	"name": "Name must match the name of one entry in pod.spec.resourceClaims of the Pod where this field is used. It makes that resource available inside a container.",
+	"":        "ResourceClaim references one entry in PodSpec.ResourceClaims.",
+	"name":    "Name must match the name of one entry in pod.spec.resourceClaims of the Pod where this field is used. It makes that resource available inside a container.",
+	"request": "Request is the name chosen for a request in the referenced claim. If empty, everything from the claim is made available, otherwise only the result of this request.",
 }
 
 func (ResourceClaim) SwaggerDoc() map[string]string {