Give the downloaded state (icon) to imported chapters

[Palloxin]

Describe your suggested feature

just this, change it to the Downloaded icon.

Other details

Maybe not full white like normal chapters since it is imported. I also guess it needs a new logic since the user shouldn't be abke to delete them normally like usual entries.

Acknowledgements

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• [X] I have updated the app to version 1.1.18.
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