Add an IngressController option to use PROXY protocol with IBM Cloud load-balancers

 
This epic tracks the API and implementation work to provide the cluster admin with an option in the IngressController API to use PROXY protocol with IBM Cloud load-balancers. 

This epic extends the IngressController API essentially by copying the option we added in NE-330.  In that epic, we added a configuration option to use PROXY protocol when configuring an IngresssController to use a NodePort service or host networking.  With this epic (NE-1090), the same configuration option is added to use PROXY protocol when configuring an IngressController to use a LoadBalancer service on IBM Cloud.