##### SUMMARY
Move some helper functions from `vmware_host_config_manager` to `PyVmomi`.

##### ISSUE TYPE
- Feature Idea

##### COMPONENT NAME
vmware_host_config_manager
vmware

##### ADDITIONAL INFORMATION
`vmware_host_config_manager` has some helper functions (`is_integer`, `is_boolean` and `is_truthy`) to deal with vSphere Web Services API `OptionValue`s. Today, I started to work on issue #61421 and I think these helper functions could be useful there, too. Actually, there are several Managed Object Types with an `OptionValue[]` parameter. Instead of duplicating the code, I think it would be better to move these helper functions to `PyVmomi` in `module_utils/vmware.py`.
result = {}
    for opts in vm.config.extraConfig:
        for optkeyname in ['enabled', 'ip', 'port', 'password']:
            if opts.key.lower() == "remotedisplay.vnc." + optkeyname:
                result[optkeyname] = opts.value
    return result
def vmware_argument_spec():
    return dict(
        hostname=dict(type='str',
                      required=False,
                      fallback=(env_fallback, ['VMWARE_HOST']),
                      ),
        username=dict(type='str',
                      aliases=['user', 'admin'],
                      required=False,
                      fallback=(env_fallback, ['VMWARE_USER'])),
        password=dict(type='str',
                      aliases=['pass', 'pwd'],
                      required=False,
                      no_log=True,
                      fallback=(env_fallback, ['VMWARE_PASSWORD'])),
        port=dict(type='int',
                  default=443,
                  fallback=(env_fallback, ['VMWARE_PORT'])),
        validate_certs=dict(type='bool',
                            required=False,
                            default=True,