Fix Mizar single yaml deployment SSH issue and add feature-gate for eBPF EDT QoS feature

[vinaykul]

What does this change do? This PR fixes issue that caused ssh connectivity to break due to eBPF EDT bandwidth QoS feature. It also adds a feature-gate to control whether EDT QoS feature is enabled or disabled. (It is currently default disabled for single-yaml deployment but enabled for kind-setup.) There are also some misc cleanups and housekeeping changes along with this.

Why is it needed? Fixes issue https://github.com/CentaurusInfra/mizar/issues/501

How was this tested? Manual testing:

• In kind-setup, deployed cluster and verified with testpod.yaml that bandwidth is policed by eBFP EDT program when map is configured with a rate-limit.
• In AWS (kubeadm setup), verified with testpod.yanl:
  • with FEATUREGATE_BWQOS set to false, netpod1/2/3 send/recv traffic without any rate limiting.
  • with FEATUREGATE_BWQOS set to true, netpod1/2/3 send/recv traffic with bandwidth policing when eBFP map is configured with a bandwidth limit.

Are there any user facing / API changes? No.

[vinaykul]

I discovered an intermittent issue where low-priority pod traffic does not have connectivity when that pod is located on a host that is also bouncer for the pod. I fixed this issue (change https://github.com/CentaurusInfra/mizar/pull/502/commits/19363640f048aa8575127ce5a0e61c051eaa0afd) and reviewed it with Phu offline.