Ree porting existing tests lp1377158

- fixing e2e tests that were broken because of an error in login.

- Finish the migration of all unit tests. Fix all issues in the tests.

- Create a new js bundle for contentfeeds.

- Cleanup and fixing smaller things on the go.

With this the migration to a state-of-the-art frontend test environment has completed. Although, not all existing selenium tests have been ported yet.