fix: The preview image is not displayed in the properties window of the file in trash

[liyigang1]

The interface for calling the file of fileinfo to obtain the thumbnail

Log: The preview image is not displayed in the properties window of the file in trash
Bug: https://pms.uniontech.com/bug-view-260617.html

[deepin-ci-robot]

deepin pr auto review

关键摘要:

• 在setFileIcon函数中，对localUrl的访问应该在fileInfo->canAttributes(CanableInfoType::kCanRedirectionFileUrl)检查之后，以确保在调用fileInfo->urlOf时fileInfo不为空。
• fileInfo->extendAttributes(ExtInfoType::kFileThumbnail).value<QIcon>()可能会导致空指针异常，应该添加空指针检查。
• icon.isNull()的检查应该在icon = QPixmap::fromImage(img);之后，以确保在尝试设置fileIcon的pixmap之前icon不为空。
• icon.pixmap(128, 128).scaled的调用应该在icon不为空的前提下进行，以避免潜在的空指针异常。

是否建议立即修改:
是

[deepin-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: liyigang1, max-lvs

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