Fix issue with cv_container and relative topology

[titom73]

Summary:

Update code to support deletion of container topology not using CVP root
container.

Deletion example:

    CVP_CONTAINERS:
      POD01:
        parent_container: Leafs

Fix: #173

Tested with :

• Addition of a complete topology
• Deletion of POD01
• Creation with partial topology already deployed
• Deletion of full topology

Types of changes

• Bug fix (non-breaking change which fixes an issue)

Related Issue(s)

Fix: #173

Proposed changes

How to test

1. Create topology:

- name: Container Management in Cloudvision
  hosts: cv_server
  connection: local
  gather_facts: false
  collections:
    - arista.avd
    - arista.cvp
  vars:
    run_tasks: false
    run_mode: merge
    CVP_CONTAINERS:
      DC2:
        parent_container: Tenant
      Leafs:
        parent_container: DC2
      Spines:
        parent_container: DC2
      POD01:
        parent_container: Leafs

  tasks:
    - name: "collect CV facts on {{inventory_hostname}}"
      arista.cvp.cv_facts:
      register: CVP_FACTS

    - name: 'running cv_container in {{run_mode}} on {{inventory_hostname}}'
      arista.cvp.cv_container:
        cvp_facts: "{{CVP_FACTS.ansible_facts}}"
        topology: "{{CVP_CONTAINERS}}"
        mode: '{{run_mode}}'
      register: result

    - debug:
        msg: '{{result}}'

2. Delete topology

- name: Container Management in Cloudvision
  hosts: cv_server
  connection: local
  gather_facts: false
  collections:
    - arista.avd
    - arista.cvp
  vars:
    run_tasks: false
    run_mode: delete
    CVP_CONTAINERS:
      POD01:
        parent_container: Leafs

  tasks:
    - name: "collect CV facts on {{inventory_hostname}}"
      arista.cvp.cv_facts:
      register: CVP_FACTS

    - name: 'running cv_container in {{run_mode}} on {{inventory_hostname}}'
      arista.cvp.cv_container:
        cvp_facts: "{{CVP_FACTS.ansible_facts}}"
        topology: "{{CVP_CONTAINERS}}"
        mode: '{{run_mode}}'
      register: result

    - debug:
        msg: '{{result}}'

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• All new and existing tests passed (make linting and make sanity-lint).