##### 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 = dict()
    interval = 15
    while timeout > 0:
        if vm.runtime.powerState.lower() == 'poweredoff':
            break
        time.sleep(interval)
        timeout -= interval
    else:
        result['failed'] = True
        result['msg'] = 'Timeout while waiting for VM power off.'
    return result
class PyVmomi(object):
    def __init__(self, module):
        """
        Constructor
        """
        if not HAS_REQUESTS:
            module.fail_json(msg=missing_required_lib('requests'),
                             exception=REQUESTS_IMP_ERR)
        if not HAS_PYVMOMI:
            module.fail_json(msg=missing_required_lib('PyVmomi'),
                             exception=PYVMOMI_IMP_ERR)
        self.module = module
        self.params = module.params
        self.current_vm_obj = None
        self.si, self.content = connect_to_api(self.module, return_si=True)
        self.custom_field_mgr = []
        if self.content.customFieldsManager:  
            self.custom_field_mgr = self.content.customFieldsManager.field
    def is_vcenter(self):