pkg/cri/server: experimental NRI integration for CRI.

Implement the adaptation interface required by the NRI
service plugin to handle CRI sandboxes and containers.
Hook the NRI service plugin into CRI request processing.

Signed-off-by: Krisztian Litkey <krisztian.litkey@intel.com>

contrib/fuzz/cri_server_fuzzer.go

@@ -38,7 +38,7 @@ func FuzzCRIServer(data []byte) int {
 	}
 	defer client.Close()
 
-	c, err := server.NewCRIService(criconfig.Config{}, client)
+	c, err := server.NewCRIService(criconfig.Config{}, client, nil)
 	if err != nil {
 		panic(err)
 	}