Dashboard content block implementation

Implemented My Content Block view basing on the view available there: http://prototype.pm.ez.no:8185
The main purpose was to get to know with how the whole PlatformUI environment works - a training purpose - and try to develop a part of that system in form of My Content Block.
Due to lacking REST endpoints I wasn't able to implement both lists: drafts and pending articles. Drafts list is fetched using REST API, but pending articles list is a static content.
Tests are still in development.