add files for upgrade tests

[vepatel]

Proposed changes

This PR adds files and makes changes to create resources for upgrade testing.

Usage:
Create: make upgrade-resources PYTEST_ARGS="create"
Delete: make upgrade-resources PYTEST_ARGS="delete"

Output:

~/nginx/kubernetes-ingress/tests on tests/upgrade-test-resources ● ● ● λ make upgrade-resources PYTEST_ARGS="create"

 ~/nginx/kubernetes-ingress/tests on tests/upgrade-test-resources ● ● λ k get vs -A && k get ing -A && k get ts -A 
NAMESPACE   NAME   STATE   HOST               IP              PORTS      AGE
ns-1        vs-1   Valid   vs-1.example.com   104.199.58.78   [80,443]   7m26s
NAMESPACE   NAME        CLASS   HOSTS                   ADDRESS         PORTS     AGE
ns-1        ingress-1   nginx   ingress-1.example.com   104.199.58.78   80, 443   7m26s
NAMESPACE   NAME   STATE   REASON           AGE
ns-1        ts-1   Valid   AddedOrUpdated   7m26s

~/nginx/kubernetes-ingress/tests on tests/upgrade-test-resources ● ● ● λ make upgrade-resources PYTEST_ARGS="delete"

~/nginx/kubernetes-ingress/tests on tests/upgrade-test-resources ● ● λ k get vs -A && k get ing -A && k get ts -A
No resources found
No resources found
No resources found

Checklist

Before creating a PR, run through this checklist and mark each as complete.

• I have read the CONTRIBUTING doc
• I have added tests that prove my fix is effective or that my feature works
• I have checked that all unit tests pass after adding my changes
• I have updated necessary documentation
• I have rebased my branch onto main
• I will ensure my PR is targeting the main branch and pulling from my branch from my own fork