[iOS] Missed top panel on "Downloads" page

[sergeymomot]

On the Downloads page missed top panel with Back button and controller name ("Downloads"), as a result, user cannot return back from the Downloads page:

• open Course Home tab and find video content (or switch to Video tab)
• tap Download button to download multiple videos
• tap on Downloading indicator
• try returning to the content list
• Result: there is no Back button

https://github.com/openedx/openedx-app-ios/assets/2964930/6c4e149d-9e03-4aab-97b1-4037496998fc

Need to return the top panel of the Download controller with "Back" button and the name of the controller.