Download errors are not properly handled

[veloman-yunkan]

kiwix-desktop's download manager ignores the possibility that a download may fail to start (or be interrupted) because of an error.

[rohit9625]

Hey @veloman-yunkan, I want to contribute to Kiwis. Are you working on this issue, or can I take it up?

[kelson42]

@rohit9625 What is your approach to fix it?

[rohit9625]

Give me some time, and I'll get back to you with an approach to implementing error handling for downloads. I didn't look at the related code yet. Just thought it's better to ask before starting working on this issue :)