Course selection is lost when navigating to a non-course-specific page

[sayravai]

When a user has selected a course, and then navigates to Privacy notice page, for example, the current course selection is lost until reselected via the Select course menu or the front page (or using the back button). From the user perspective, it would be a good idea to keep the current selection in local storage so it does not need to be reselected. Also the course menu could be shown at all times.

Note: this should be discussed along with the site/course language selection, as that adds to the somewhat confusing UX.

[sayravai]

This old issue might also be related/considered at the same time: #366