Links: Distinguish between clicked and connected links

* Modifies highlightLink and removeLinkHighlight methods
  so they add different classes for clicked and connected links
* Adds new class .cx-highlight--lightblue to source and translation
  less files for connected link highlights

Change-Id: Ie5016abd48e3f45369ca6beb3303d5dc18f4e466
Merge "Links: Distinguish between clicked and connected links"