Make opened covers close upon clicking back button instead of the whole entry screen

[Palloxin]

Describe your suggested feature

1. Go to an entry, click on the cover.
2. Click back button of android nav bar The entry screen will close

The suggestion is about making it just close the "opened" cover without exiting the entry screen.

Current:

https://github.com/user-attachments/assets/3226f1f4-61ab-48a6-8315-88aaea2ba5db

Expected:

https://github.com/user-attachments/assets/e15c733a-0853-411d-95c9-659ae5800cca

Other details

Another section of the app requires the same kind of "fix" #846

Acknowledgements

• [X] I have searched the existing issues and this is a new ticket, NOT a duplicate or related to another open or closed issue.
• [X] I have written a short but informative title.
• [X] If this is an issue with a source, I should be opening an issue in the sources repository.
• [X] I have updated the app to version 2.0.0.
• [X] I will fill out all of the requested information in this form.