enhancements to exposure-analysis

[shireenf-ibm]

• consider not returning an internal interface in the exposed result more info

• handling cases of labels containment with same conns (more info)

• in representative_selectors.go, func SelectorsFullMatch decide whether to accept an empty rule as a full-match with non-empty representative-peer's selectors or not (currently is considered as full-match)

• output enhancement: currently MatchExpressions of a LabelSelector are written using v1.LabelSelectorRequirement.String ; which returns an extra , at the end of the requirement.
  consider if to remove that , from the end of the resulted string