<!--- 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 -->
This feature would implement a ClearSessions command for the Sessions category of redfish_command, to clear all active sessions.

##### ISSUE TYPE
- Feature Idea

##### COMPONENT NAME
<!--- Write the short name of the module, plugin, task or feature below, use your best guess if unsure -->
redfish_command.py
redfish_utils.py

##### ADDITIONAL INFORMATION
<!--- Describe how the feature would be used, why it is needed and what it would solve -->
This command would help user to clear all active sessions.

<!--- Paste example playbooks or commands between quotes below -->
```yaml

```

<!--- HINT: You can also paste gist.github.com links for larger files -->

if response['ret'] is False:
                return response
            data = response['data']
            if '"' + nic_addr + '"' in str(data) or "'" + nic_addr + "'" in str(data):
                target_ethernet_uri = uri
                target_ethernet_current_setting = data
                break
        if target_ethernet_uri is None:
            return {'ret': False, 'msg': "No matched EthernetInterface found under Manager"}
        
        payload = {}
        for property in nic_config.keys():
            value = nic_config[property]
            if property not in target_ethernet_current_setting:
                return {'ret': False, 'msg': "Property %s in nic_config is invalid" % property}
            if isinstance(value, dict):
                if isinstance(target_ethernet_current_setting[property], dict):
                    payload[property] = value
                elif isinstance(target_ethernet_current_setting[property], list):
                    payload[property] = list()
                    payload[property].append(value)
                else:
                    return {'ret': False, 'msg': "Value of property %s in nic_config is invalid" % property}
            else:
                payload[property] = value
        
        need_change = False
        for property in payload.keys():
            set_value = payload[property]
            cur_value = target_ethernet_current_setting[property]