proto: update to latest grpc protobuf gen tools

Modeled after:
container-storage-interface/spec#552

Update to the latest, non-deprecated versions of Google's tools for
protobuf generation.

Also update make tools to allow working with go modules outside of
GOPATH, and to build on ARM-based Macbooks.

New tools are significantly different from prior tools. Notably, the
grpc plugin is no longer supported, so the `--go-gprc_out` flag is used,
which moves some generated content from `cosi.pb.go` to a new
`cosi_grpc.pb.go` file.

We are still able to keep fake-gen by continuing to use deprecated tool
versions for that purpose. There's a chance that it may not serve the
COSI project long-term, but it should still work for now.

Signed-off-by: Blaine Gardner <[email protected]>

Author: BlaineEXE

proto/Makefile

@@ -4,7 +4,7 @@ package cosi.v1alpha1;
 
 import "google/protobuf/descriptor.proto";
 
-option go_package = "sigs.k8s.io/container-object-storage-interface-spec;cosi";
+option go_package = "sigs.k8s.io/container-object-storage-interface-api/proto;cosi";
 
 extend google.protobuf.EnumOptions {
     // Indicates that this enum is OPTIONAL and part of an experimental
@@ -166,7 +166,7 @@ message DriverCreateBucketRequest {
 }
 
 message DriverCreateBucketResponse {
-    // bucket_id returned here is expected to be the globally unique 
+    // bucket_id returned here is expected to be the globally unique
     // identifier for the bucket in the object storage provider.
     string bucket_id = 1;
 
@@ -178,7 +178,7 @@ message DriverCreateBucketResponse {
 message DriverDeleteBucketRequest {
     // This field is REQUIRED
     // bucket_id is a globally unique identifier for the bucket
-    // in the object storage provider 
+    // in the object storage provider
     string bucket_id = 1;
 
     // This field is OPTIONAL
@@ -194,7 +194,7 @@ message DriverDeleteBucketResponse {
 message DriverGrantBucketAccessRequest {
     // This field is REQUIRED
     // bucket_id is a globally unique identifier for the bucket
-    // in the object storage provider 
+    // in the object storage provider
     string bucket_id = 1;
 
     // This field is REQUIRED
@@ -215,7 +215,7 @@ message DriverGrantBucketAccessRequest {
 message DriverGrantBucketAccessResponse {
     // This field is REQUIRED
     // This is the account_id that is being provided access. This will
-    // be required later to revoke access. 
+    // be required later to revoke access.
     string account_id = 1;
 
     // This field is REQUIRED