* Add custom thumbnail url. Support backup & restore
- add custom thumbnail url in edit info/custom
- include it in backup n restore
* increase chop char
* edit chop char again to match screenshoot
* tweak truncating middle part
* apply edited cover to history, updates , others
* simplify placeholder logic
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Co-authored-by: jobobby04 <jobobby04@users.noreply.github.com>