<!--- Verify first that your feature was not already discussed on GitHub -->
<!--- Complete *all* sections as described, this form is processed automatically -->

##### SUMMARY
<!--- Describe the new feature/improvement briefly below -->
Ansible by default only creates LUKS1 format devices. Considering LUKS2 extra features and age, I think it would be beneficial to allow users to create LUKS2 devices.

##### ISSUE TYPE
- Feature Idea

##### COMPONENT NAME
luks_device

##### ADDITIONAL INFORMATION
<!--- Describe how the feature would be used, why it is needed and what it would solve -->
For reliability, one should use either disk UUID's or labels. UUID's are (in my opinion) a hassle when it comes to using them in Ansible.

Enter labels. Labels can be the same across multiple hosts, and will be tied to the right disk/partition, even if sda1 suddenly becomes sdb1 after some hardware reconfiguration.

Now, the LUKS1 format, which Ansible creates by default with the `luks_device` module, does not support labels... Support was added with LUKS2.

It should be noted that, from what I can see, the module *does already support removing keys from LUKS2 format devices*.

<!--- Paste example playbooks or commands between quotes below -->
```yaml
- name: create LUKS2 container
  luks_device:
    device: "/dev/loop0"
    state: "present"
    keyfile: "/vault/keyfile"
    format: luks2
```
return (self.device is not None and
                self._module.params['keyfile'] is not None and
                self._module.params['state'] in ('present',
                                                 'opened',
                                                 'closed') and
                not self._crypthandler.is_luks(self.device))
    def opened_luks_name(self):
        ''' If luks is already opened, return its name.
            If 'name' parameter is specified and differs
            from obtained value, fail.
            Return None otherwise
        '''
        if self._module.params['state'] != 'opened':
            return None
        
        name = self._crypthandler.get_container_name_by_device(self.device)
        if name is None:
            
            return None
        if self._module.params['name'] is None:
            
            return name
        if name != self._module.params['name']:
            
            
            self._module.fail_json(msg="LUKS container is already opened "
                                   "under different name '%s'." % name)
        
        return name
    def luks_open(self):