Assign secondary IP-Address to Interface

[nerdfunk-net]

Closes: #389

What's Changed

This PR adds the ability to assign a secondary IP to an interface. You can use this example to parse the output of show ip interface (eg. Cisco xe)

commands:
  - command: "show ip interface"
    parser: "textfsm"
    jpath: "[?interface=='{{ current_key }}'].{ip_address: ip_address, prefix_length: prefix_length}"
    post_processor: "{{ obj | parse_cisco_xe_show_ip_interface | tojson }}"

To Do

• Explanation of Change(s)
• Added change log fragment(s) (for more information see the documentation)
• Attached Screenshots, Payload Example
• Unit, Integration Tests
• Documentation Updates (when adding/changing features)
• Outline Remaining Work, Constraints from Design

[jeffkala]

@Dav-C probably need you to look at this one. Seems like more would be needed.