The VNF details are retrieved using VNF mgmt IP address
(parameter: mgmt_url) received in "show_vnf" API response.
But this functionality was failing as "mgmt_url" parameter was
missing from API response.
Reason:
Earlier in tacker, VNF mgmt IP address was assigned to parameter
named "mgmt_url". But in [1] it was changed to "mgmt_ip_address".
This patch replaces "mgmt_url" to "mgmt_ip_address" for vnf as well
as for vnffg details retrieval.
[1] https://review.opendev.org/c/openstack/tacker/+/490471
Closes-Bug: #1899740
Change-Id: I47d8cb12ae004a8b927277ee1fe222daa800214f