Detect Duplicates before Downloading

[Tommy-01]

Describe your suggested feature

When you try to start downloading of something, that is already localy stored, there should be a notice like "Already downloaded, download again yes/no".
The Hendroid app (https://github.com/Nonononoki/Hendroid) has this function.

Acknowledgements

• I have searched the existing issues and this is a new ticket, NOT a duplicate or related to another open issue.