CIFS or remote path support for downloaded content

[aqsede]

Describe your suggested feature

Extending over previous #1120 since it is locked by @kshannoninnes

I am not able to make it work at all using CIFS Documents Provider,

It's stuck on downloading and the downloaded chapter doesn't get recognized.
If I'm using internal storage it will immediately trigger checking download but not if using CIFS Documents Provider, no loading happen at all.

Additional observation:

• Downloading any test chapter indicate there is a file created on the remote path but completion is an issue like "Page not Found"
• I can read online without issue, only download to remote path is not working
• Backup most of the time work on the remote folder.

Was there changes since that break this (I am assuming this is unsupported/unintended anyway) feature?

Other details

No response

Acknowledgements

• I have searched the existing issues and this is a new ticket, NOT a duplicate or related to another open or closed issue. #1741
• I have written a short but informative title.
• I have updated the app to version 0.17.1.
• I will fill out all of the requested information in this form.