Fix all styling issues and bugs

The following styling issues and bugs have been reported that need to be fixed: 

1. Messenger MFE sidebar is hidden in RTL view.
2. The header's nav-bar is inconsistent in MFE and legacy pages.
3. Styling issues in course filter facets on the discovery page.
4. Reports pages do not have margins.
5. Indigo theme not applied to Learner Record MFE.
6. Language Widget missing from Authoring MFE.