Help flag for admin command does not work for subcommands

[ddanielr]

Describe the bug
When using the ./accumulo admin command, help flags -h, --help, -help, -? will only work at the top level, and will throw an error if set on any subcommand.

./accumulo admin volumes -h
Thread 'admin' died.
com.beust.jcommander.ParameterException: Was passed main parameter '-h' but no main parameter was defined in your arg class
	at com.beust.jcommander.JCommander.initMainParameterValue(JCommander.java:961)
	at com.beust.jcommander.JCommander.parseValues(JCommander.java:762)
	at com.beust.jcommander.JCommander.parse(JCommander.java:363)
	at com.beust.jcommander.JCommander.parseValues(JCommander.java:803)
	at com.beust.jcommander.JCommander.parse(JCommander.java:363)
	at com.beust.jcommander.JCommander.parse(JCommander.java:342)
	at org.apache.accumulo.server.util.Admin.execute(Admin.java:342)
	at org.apache.accumulo.start.Main.lambda$execKeyword$0(Main.java:81)
	at java.base/java.lang.Thread.run(Thread.java:842)

Due to the amount of subcommands, the top-level usage statement is large and typically scrolls off a terminal window.

Versions (OS, Maven, Java, and others, as appropriate):

• Affected version(s) of this project: [e.g. 1.10.0] 2.1.x

To Reproduce
Steps to reproduce the behavior (or a link to an example repository that reproduces the problem):

1. Run the accumulo admin command with any subcommand and add any of the help flags ./accumulo admin dumpConfig --help
2. See a Parameter Exception stack trace

Expected behavior
The help flag should work with any subcommand used in the admin command

[jmark99]

@ddanielr looking at the accumulo admin command usage states:

Usage: accumulo admin [options] [command] [command options]                                                                                       
  Options:                                                                                                                                        
    -auths, --auths                                                      
      the authorizations to use when reading or writing                                                                                           
      Default: <empty string>                                                                                                                     
    -c, --config-file                                                                                                                             
      Read the given client config file. If omitted, the classpath will be                                                                        
      searched for file named accumulo-client.properties                 
    -f, --force                                                          
      force the given server to stop by removing its lock                                                                                         
      Default: false                                                                                                                              
    -h, -?, --help, -help    
	......

The usage indicates that the help flags should appear between the admin and command values. None of the sub- commands themselves have any help flags listed. It appears the initial code only provided a help command for the overall admin command.

I went through each sub-command and If you execute each sub-command using that format no errors are thrown, but rather the entire accumulo admin help message is displayed.

The one exception is the randomizeVolumes command. This command will throw an exception if the -t <table> info is not provided.

I agree that it would nice if help info would be provided if a help flag was used anywhere on the command line, but I'm not sure if this is a bug or just a design choice that was made. I'm not sure how to best let the user know that the help flags should be earlier on the command line. Perhaps it should be considered an enhancement/improvement issue instead. What are your thoughts?