<!--- 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 -->

username: "{{ username }}"
      password: "{{ password }}"
  - name: Set one-time boot device to BootNext target of "Boot0001"
    redfish_command:
      category: Systems
      command: SetOneTimeBoot
      resource_id: 437XR1138R2
      bootdevice: "UefiBootNext"
      boot_next: "Boot0001"
      baseuri: "{{ baseuri }}"
      username: "{{ username }}"
      password: "{{ password }}"
  - name: Set chassis indicator LED to blink
    redfish_command:
      category: Chassis
      command: IndicatorLedBlink
      resource_id: 1U
      baseuri: "{{ baseuri }}"
      username: "{{ username }}"
      password: "{{ password }}"
  - name: Add user
    redfish_command:
      category: Accounts
      command: AddUser
      baseuri: "{{ baseuri }}"
      username: "{{ username }}"
      password: "{{ password }}"
      new_username: "{{ new_username }}"
      new_password: "{{ new_password }}"
      roleid: "{{ roleid }}"