Improve i18n on the LMS dashboard course listing page

Adding translator comments to the dashboard.

Updating alt text to verification pending ribbon.

fix tests
ECOM-811 design and layout changes
Merge pull request #6376 from edx/improve-i18n-dashboard-course-listing

Improve i18n on the LMS dashboard course listing page
Merge pull request #6364 from edx/alasdair/decoupled-verified

ECOM-811 design and layout changes
mattdrayer/entrance-exams: New Feature - Course Entrance Exams