fix: [AA-1018] api refactor

This is the first step toward clearing out the redundant metadata from the
coursewareMetadata and getting it from a common source - the courseHomeMetadata.

remove username from coursewareMetadata
Remove courseAccess from coursewareMetadata.

Fix all unit tests
Modify classes that use metadataModel to use courseHomeMetadata for common data.
metadataModel still exists as a mechanism to distinguish if a component is under
courseware or courseHome, and it will be renamed or removed in a later refactor.

src/shared/data/__factories__/courseMetadataBase.factory.js

@@ -5,9 +5,9 @@ import { Factory } from 'rosie'; // eslint-disable-line import/no-extraneous-dep
 import './tab.factory';
 
 export default new Factory()
-  .sequence('id', (i) => `course-v1:edX+DemoX+Demo_Course_${i}`)
   .option('host')
   .attrs({
+    id: 'course-v1:edX+DemoX+Demo_Course_1',
     is_staff: false,
     original_user_is_staff: false,
     number: 'DemoX',