Add parameter validations for commands in HBase shell

One of our customers got confused with "balance_switch" command in HBase shell.

They mistakenly ran "balance_swich status" command instead of "balancer_enabled" command to see if the balancer is enabled. However, like the following, it didn't cause any errors and it looks like the command was successful.

hbase> balance_switch status
1 active master, 0 backup masters, 1 servers, 0 dead, 2.0000 average load
Took 0.0055 seconds
Previous balancer state : true
Took 0.0041 seconds
=> "true"

To make matters worse, the "balance_swich status" command will make the balancer disabled.

Of course, the command was wrong but I think that's a little bit confusing. So I think we need to add parameter validations for commands in HBase shell. I'll check if we need to add validations for any other commands in this Jira.