CLI: Add the -h short-hand flag for --help to verdi

[sphuber]

Fixes #5790

[sphuber]

Before we accept this, I want to still want to quickly check whether there currently are not commands out there that already use -h. The tests pass, but it is possible that this is not covered by the tests.

[sphuber]

Ok, I checked with the script below, and there is no verdi command that has the -h flag:

import click
from aiida.cmdline.commands.cmd_verdi import verdi

def recurse_commands(ctx, command: click.Command):
    """Recursively return all subcommands that are part of ``command``.

    :param command: The click command to start with.
    :param parents: A list of strings that represent the parent commands leading up to the current command.
    :returns: A list of strings denoting the full path to the current command.
    """
    if isinstance(command, click.Group):
        for command_name in command.commands:
            yield from recurse_commands(ctx, command.get_command(ctx, command_name))
    yield command

ctx = click.Context(verdi)

for command in recurse_commands(ctx, verdi):
    for param in command.params:
        if not isinstance(param, click.Option):
            continue
        option = param
        if '-h' in option.opts:
            print(option.opts)