Make endpoint picker connection flags configurable

[salonichf5]

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Proposed changes

Write a clear and concise description that helps reviewers understand the purpose and impact of your changes. Use the following format:

Problem: User should be able to configure Endpoint picker connection flags

Solution: Adds command line support for endpoint picker flags

Testing: Manual testing

Binary testing for flag

./gateway controller --gateway-ctlr-name="gateway.nginx.org/nginx-gateway-controller" --gatewayclass=nginx                                                                           
epp flags in controller command: false true
epp flags in epp command: false true

    Args:
      controller
      --gateway-ctlr-name=gateway.nginx.org/nginx-gateway-controller
      --gatewayclass=nginx
      --config=nginx-gateway-config
      --service=nginx-gateway-nginx-gateway-fabric
      --agent-tls-secret=agent-tls
      --metrics-port=9113
      --health-port=8081
      --leader-election-lock-name=nginx-gateway-nginx-gateway-fabric-leader-election
      --endpoint-picker-tls-skip-verify=true

default flags for NGF container

Endpoint picker default

   endpoint-picker-shim:
    Image:           nginx-gateway-fabric:sa.choudhary
    Port:            <none>
    Host Port:       <none>
    SeccompProfile:  RuntimeDefault
    Command:
      /usr/bin/gateway
      endpoint-picker
      --endpoint-picker-tls-skip-verify

Update adding/updating flags

      --gateway-api-experimental-features
      --gateway-api-inference-extension
      --endpoint-picker-tls-skip-verify=false
      --endpoint-picker-disable-tls
      --snippets-filters


sa.choudhary@N9939CQ4P0 nginx-gateway-fabric % k logs gateway-nginx-68754cc8df-h5mkv endpoint-picker-shim
epp flags in epp command: false true

Please focus on (optional): If you any specific areas where you would like reviewers to focus their attention or provide specific feedback, add them here.

Closes #4090

Checklist

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

Release notes

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