* [BUGFIX] Fix slow album thumbnail generation
When generating the thumbnail of an album, all of the pictures of the
album are retrieved but only the first picture of the album is used.
Retrieving all of the pictures of the album at once can cause huge performance
issues on large albums.
Since only the first picture is used to generate the thumbnail, this commit
uses the getAssetListPaged method instead of getAssetListRange, effectively
retrieving only the first picture of the album.
* [DEVMINOR] Remove unecessary check
As we already check for the number of assets in the album, when
fetching assets using `album.getAssetListPaged` the returned result
won't be empty.
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Co-authored-by: Azsde <aelkaim@pixium-vision.com>
8a421eb778