Removing VN association from IPAM page

Removing VN association from IPAM page.

UT Cases:
Verify through config api server REST APIs for each steps mentioned below.
http://nodeip:8082/virtual-networks
http://nodeip:8082/virtual-network/<vn_uuid>
http://nodeip:8082/network-ipams
http://nodeip:8082/network-ipam/<ipam_uuid>

1) Created new IPAM "adminIpam" in 'admin' project. 
Verify if new IPAM is created.
Result: Pass

2) Created new  IPAM "demoIpam" in 'demo' project.
Verify if new IPAM is created.
Result: Pass

3) Created new VN "adminVN" in 'admin' project.
Verify if new VN is created.
Result: Pass

4) Created new VN "demoVN" in 'demo' project.
Verify if new VN is created.
Result: Pass

5) Edit VN "adminVN" and associate IPAM "adminIpam" with subnets 192.168.1.0/24, 192.168.11.0/24.
Also associate IPAM "demoIpam" with 192.168.2.0/24, 192.168.22.0/24.
Verify if "adminVN" is associated with both IPAMs "adminIpam" and "demoIpam".
Result: Pass

6) Edit VN "demoVN" and associate IPAM "demoIpam" with subnets 192.168.3.0/24, 192.168.33.0/24.
Also associate IPAM "adminIpam" with 192.168.4.0/24, 192.168.44.0/24.
Verify if "demoVN" is associated with both IPAMs "adminIpam" and "demoIpam".
Result: Pass

7) Go to IPAM page. 
Verify if "adminIpam" is associated with both "adminVN" and "demoVN". Also verify if "demoIpam" is associated with both "adminVN" and "demoVN".
Result: Pass

8) Edit IPAM "adminIpam" by changing values for "DNS Method" "NTP Server" and "Domain name" and Save. Verify the associated VNs for both "adminIpam" and "demoIpam" and respective subnets are not impacted.
Result: Pass

9) Repeat step 7 for various types of "DNS Method" 
Verify the associated VNs for both "adminIpam" and "demoIpam" and respective subnets are not impacted.
Result: Pass

10) Delete "demoIpam". 
Verify if delete error with a proper description(for VN association) is shown
Result: Pass

11) Go to Networks page. Delete "adminVN". 
Verify if delete error with a proper description(for IPAM association) is shown.
Result: Pass

12) Launch an instance from Horizon in "adminVN". 
Verify if the instance gets ip address from one of the subnets associated with "adminVN"
Result: Pass

13) Repeat Step 11
Result: Fail
Reason: Known issue.

14) Terminate instance from Horizon. Repeat Steps 11, 10(Assuming the instance ip address is from "demoIpam")
Result: Pass

15) Disaasociate both IPAMs from VN "adminVN" from networks page. Save.
Verify if both IPAMs are disassociated from VN "adminVN" in both Networks page and IPAM page.
Result: Pass

16) Repeat Step 15 for "demoVN". 
Verify if both IPAMs are disassociated from VN "demoVN" in both Networks page and IPAM page.
Result: Pass

17) Delete IPAM "demoIpam" through IPAM page.
Verify if IPAM "demoIpam" is deleted. Also check there are no references of "demoIpam" to any of the VNs.
Result: Pass

18) Repeat Step 15 for "demoVN".
Verify if both IPAMs are disassociated from VN "demoVN" in both Networks page and IPAM page.
Result: Pass

19) Delete VN "demoVN" from Networks page.
Verify if "demoVN" is deleted successfully, in both Networks page and IPAM page.
Result: Pass