[WIP] PIM-765 Created the Widget Registry

```
Bug fix: no
Feature addition: yes
Backwards compatibility break: no
Unit test passes: yes
Specs passes: yes
Replaced unit test classes removed: not needed
Behat scenario passes: yes
Checkstyle issues: no
ChangeLog updated: yes
Documentation PR: 
Fixes the following jira:
 - PIM-765
```