namespace port group is cleaned up on restart

Description of problem:

The problem was that namespace handler on initial sync would delete all ports (because logical port cache where it got lsp UUIDs wasn't populated) and all acls (they were just set to nil). Even though both ports and acls will be re-added by the corresponding handlers, it may cause disruption.

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:

1. create a namespace with at least 1 pod and egress firewall in it

2. pick any ovnkube-node pod, find namespace port group UUID in nbdb by external_ids["name"]=<namespace name>, e.g. for "test" namespace

_uuid               : 6142932d-4084-4bc3-bdcb-1990fc71891b
acls                : [ab2be619-1266-41c2-bb1d-1052cb4e1e97, b90a4b4a-ceee-41ee-a801-08c37a9bf3e7, d314fa8d-7b5a-40a5-b3d4-31091d7b9eae]
external_ids        : {name=test}
name                : a18007334074686647077
ports               : [55b700e4-8176-42e7-97a6-8b32a82fefe5, cb71739c-ad6c-4436-8fd6-0643a5417c7d, d8644bf1-6bed-4db7-abf8-7aaab0625324] 

3. restart chosen ovn-k pod

4. check logs on restart that update chosen port group to have zero ports and zero acls

Update operations generated as: [{Op:update Table:Port_Group Row:map[acls:{GoSet:[]} external_ids:{GoMap:map[name:test]} ports:{GoSet:[]}] Rows:[] Columns:[] Mutations:[] Timeout:<nil> Where:[where column _uuid == {6142932d-4084-4bc3-bdcb-1990fc71891b}] Until: Durable:<nil> Comment:<nil> Lock:<nil> UUID: UUIDName:}] 

Actual results:

Expected results:

On restart port group stays the same, no extra update with empty ports and acls is generated

Additional info:

Please fill in the following template while reporting a bug and provide as much relevant information as possible. Doing so will give us the best chance to find a prompt resolution.

Affected Platforms:

Is it an

1. internal CI failure 
2. customer issue / SD
3. internal RedHat testing failure

If it is an internal RedHat testing failure:

• Please share a kubeconfig or creds to a live cluster for the assignee to debug/troubleshoot along with reproducer steps (specially if it's a telco use case like ICNI, secondary bridges or BM+kubevirt).

If it is a CI failure:

• Did it happen in different CI lanes? If so please provide links to multiple failures with the same error instance
• Did it happen in both sdn and ovn jobs? If so please provide links to multiple failures with the same error instance
• Did it happen in other platforms (e.g. aws, azure, gcp, baremetal etc) ? If so please provide links to multiple failures with the same error instance
• When did the failure start happening? Please provide the UTC timestamp of the networking outage window from a sample failure run
• If it's a connectivity issue,
• What is the srcNode, srcIP and srcNamespace and srcPodName?
• What is the dstNode, dstIP and dstNamespace and dstPodName?
• What is the traffic path? (examples: pod2pod? pod2external?, pod2svc? pod2Node? etc)

If it is a customer / SD issue:

• Provide enough information in the bug description that Engineering doesn’t need to read the entire case history.
• Don’t presume that Engineering has access to Salesforce.
• Please provide must-gather and sos-report with an exact link to the comment in the support case with the attachment.  The format should be: https://access.redhat.com/support/cases/#/case/<case number>/discussion?attachmentId=<attachment id>
• Describe what each attachment is intended to demonstrate (failed pods, log errors, OVS issues, etc).  
• Referring to the attached must-gather, sosreport or other attachment, please provide the following details:
  • If the issue is in a customer namespace then provide a namespace inspect.
  • If it is a connectivity issue:
    • What is the srcNode, srcNamespace, srcPodName and srcPodIP?
    • What is the dstNode, dstNamespace, dstPodName and  dstPodIP?
    • What is the traffic path? (examples: pod2pod? pod2external?, pod2svc? pod2Node? etc)
    • Please provide the UTC timestamp networking outage window from must-gather
    • Please provide tcpdump pcaps taken during the outage filtered based on the above provided src/dst IPs
  • If it is not a connectivity issue:
    • Describe the steps taken so far to analyze the logs from networking components (cluster-network-operator, OVNK, SDN, openvswitch, ovs-configure etc) and the actual component where the issue was seen based on the attached must-gather. Please attach snippets of relevant logs around the window when problem has happened if any.

• For OCPBUGS in which the issue has been identified, label with “sbr-triaged”
• For OCPBUGS in which the issue has not been identified and needs Engineering help for root cause, labels with “sbr-untriaged”
• Note: bugs that do not meet these minimum standards will be closed with label “SDN-Jira-template”