<!--- 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 -->

payload[service_name] = {}
            for service_property in manager_services[service_name].keys():
                value = manager_services[service_name][service_property]
                if service_property in ['ProtocolEnabled', 'protocolenabled']:
                    if value in protocol_state_onlist:
                        payload[service_name]['ProtocolEnabled'] = True
                    elif value in protocol_state_offlist:
                        payload[service_name]['ProtocolEnabled'] = False
                    else:
                        return {'ret': False, 'msg': "Value of property %s is invalid" % service_property}
                elif service_property in ['port', 'Port']:
                    if isinstance(value, int):
                        payload[service_name]['Port'] = value
                    elif isinstance(value, str) and value.isdigit():
                        payload[service_name]['Port'] = int(value)
                    else:
                        return {'ret': False, 'msg': "Value of property %s is invalid" % service_property}
                else:
                    payload[service_name][service_property] = value
        
        response = self.get_request(self.root_uri + self.manager_uri)
        if response['ret'] is False:
            return response
        data = response['data']
        if 'NetworkProtocol' not in data:
            return {'ret': False, 'msg': "NetworkProtocol resource not found"}
        networkprotocol_uri = data["NetworkProtocol"]["@odata.id"]
        
        response = self.get_request(self.root_uri + networkprotocol_uri)
        if response['ret'] is False: