Improve object reuse for grid messages (#18940)

Allow internal types to support a `Recycler` interface, which will allow for sharing of common types across handlers.

This means that all `grid.MSS` (and similar) objects are shared across in a common pool instead of a per-handler pool.

Add internal request reuse of internal types. Add for safe (pointerless) types explicitly.

Only log params for internal types. Doing Sprint(obj) is just a bit too messy.

cmd/storage-rest-client.go

@@ -346,6 +346,7 @@ func (client *storageRESTClient) StatVol(ctx context.Context, volume string) (vo
 		return vol, toStorageErr(err)
 	}
 	vol = *v
+	// Performs shallow copy, so we can reuse.
 	storageStatVolHandler.PutResponse(v)
 	return vol, nil
 }
@@ -455,6 +456,7 @@ func (client *storageRESTClient) RenameData(ctx context.Context, srcVolume, srcP
 	if err != nil {
 		return 0, toStorageErr(err)
 	}
+	defer storageRenameDataHandler.PutResponse(resp)
 	return resp.Signature, nil
 }