Finish issues found in deep link PR. Original PR was merged to get in for Apple beta.
- Test to see if deep link could potentially pull in a non-EN Wikipedia content group, if that happens to be the latest. If so, adjust content group fetching to only pull EN, since that's the only deep link we're targeting so far.
- Layout issues - Deep link header ignores safe area on the left side
- Layout issues - There's a large space when rotating (try updateScrollViewInsets)
- Nav bar title shows when the view appears. We don't want a title showing on launch if the header is visible.
- When re-creating the stack, On This Day VC is hydrated as a "from the explore feed VC" (with an X button and no nav bar) rather then the version that should be in the stack. (To replicate: Open app, open On This Day via deep link, background the app, then hard quit and re-run the app.)