Support load thumbnails from Synology @eaDir or .thumb dir

[eritpchy]

With https://github.com/eritpchy/thumbnails-docker project help, you can easily create thumbnails less than 50kb, and upload these files to cloud

loadThumbFromThumbDir --> loadThumbFromSynologyEaDir --> loadThumbFromOriginalFile

Similar queasion: https://forum.rclone.org/t/quick-thumbnails-preview-on-rcx/23663

demo

https://user-images.githubusercontent.com/8630635/133233886-3b9cab21-0a23-4987-b93d-0cb2ecc5dbdf.mp4

https://user-images.githubusercontent.com/8630635/133234082-b0a6e259-05b7-4c06-a62b-9cd72faff53f.mp4

[CLAassistant]

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