Translation & secure-aware changes to studio's settings page

1. Change the link of course's about page secure aware, which displays 'https' or 'http' prefix according to the current protocol.
2. Make the email in this page translatable.
For i18n safety, could you please put the `&quot;` inside the substitution, as well as the protocol? So this string would look like
"The course {course_display_name}, provided by {platform_name}, is open for enrollment. Please navigate to this course at {link_for_about_page} to enroll."

This is much easier for translators to deal with. Then your variables are a bit harder to define but that's OK, computer can handle:

`course_display_name = '&quot;' + context_course.display_name_with_default + '&quot;',`

`link_for_about_page = protocol + lms_link_for_about_page`

then just define a variable `protocol` before this whole format thing that is like,
`protocol = 'https:' if is_secure else 'http:'`

Does this make sense? I want everyone to get in the habit of making the i18n strings error proof from a translators point of view - it would be very easy for a translator to, for example, switch the link with the protocol. The translation software (rightly) does not check for variable ordering so when you need a certain order, it is best to enforce it another way: instead of having "blah {x}{y}", just do "blah {z}" and make z = x+y.