etcdctl/check: create new check command for memory usage

Create a new command similar to check perf that can check the memory
consumption for putting different workloads on a given endpoint. If no endpoint
is provided, localhost will be used. Return user with a message that whether
there are enough memory for a given workload with pass or fail.

Fixed #9121

etcdctl/ctlv3/command/check.go

@@ -286,6 +286,7 @@ func defrag(c *v3.Client, ep string) {
 	}
 	fmt.Printf("Defragmented %q\n", ep)
 }
+
 // NewCheckDatascaleCommand returns the cobra command for "check datascale".
 func NewCheckDatascaleCommand() *cobra.Command {
 	cmd := &cobra.Command{