<!--- 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 -->

creds = {'user': module.params['username'],
             'pswd': module.params['password']}
    
    user = {'account_id': module.params['id'],
            'account_username': module.params['new_username'],
            'account_password': module.params['new_password'],
            'account_roleid': module.params['roleid'],
            'account_updatename': module.params['update_username'],
            'account_properties': module.params['account_properties']}
    
    timeout = module.params['timeout']
    
    resource_id = module.params['resource_id']
    
    root_uri = "https://" + module.params['baseuri']
    rf_utils = RedfishUtils(creds, root_uri, timeout, module,
                            resource_id=resource_id, data_modification=True)
    
    if category not in CATEGORY_COMMANDS_ALL:
        module.fail_json(msg=to_native("Invalid Category '%s'. Valid Categories = %s" % (category, CATEGORY_COMMANDS_ALL.keys())))
    
    for cmd in command_list:
        
        if cmd not in CATEGORY_COMMANDS_ALL[category]:
            module.fail_json(msg=to_native("Invalid Command '%s'. Valid Commands = %s" % (cmd, CATEGORY_COMMANDS_ALL[category])))
    
    if category == "Accounts":
        ACCOUNTS_COMMANDS = {
            "AddUser": rf_utils.add_user,
            "EnableUser": rf_utils.enable_user,