Feature-9904: Enhancing NG-UI to enable Juju operational view dashboard

New functions implemented in N2VC (Specific for VNF)
    - update_vca_status() in n2vc.juju.conn.py
    - get_executed_actions() in libjuju.py
    - get_application_configs() in libjuju.py

Unit testing added for the above implemented new functions
    - UpdateVcaStatus in test_n2vc_juju_conn.py
    - GetExecutedActionsTest in test_libjuju.py
    - GetApplicationConfigsTest in test_libjuju.py

Change-Id: I7d750d8c39bc7bc061568c28d29f53d1b87c4c23
Signed-off-by: gspri <priyadharshini.g@tataelxsi.co.in>
Signed-off-by: ksaikiranr <saikiran.k@tataelxsi.co.in>