Increase client-go k8s config QPS and burst for better performance

By checking the code under pkg/cli, we can see

k8sConfig := config.GetConfigOrDie()

so we are using the client-go of k8s.

In the GetConfigOrDie() function, we could find that it is using

func GetConfigWithContext(context string) (*rest.Config, error) {
	cfg, err := loadConfig(context)
	if err != nil {
		return nil, err
	}

	if cfg.QPS == 0.0 {
		cfg.QPS = 20.0
		cfg.Burst = 30.0
	}

	return cfg, nil
}

Which means we are set QPS 20 and Burst 30. For better performance, I would recommend to use QPS 100 and Burst 100, same as kots https://github.com/replicatedhq/kots/pull/3523/files

Start in pkg/cli by tracing config.GetConfigOrDie() to GetConfigWithContext and verify where the client-go defaults are set. Update the QPS and burst values to the requested levels, then confirm the surrounding configuration behavior and any existing checks remain correct.