Refactor AngularJs relevance directives to components

As part of the first step in the plan to convert the Channel Manager to Angular we plan to refactor AngularJs directives to components. This user story is about all relevance related directives:

• channel/relevance/viewAs.directive.js

The complete plan can be found here: https://docs.google.com/document/d/1RoGCnJSBXrvP0kdd0jGLzWNd6Cbv1ucCpbo0YLNUN5c