allow disabling media thumbnails

[user-1-2-3-4-5]

Checklist

• I made sure that there are no existing issues - open or closed - to which I could contribute my information.
• I made sure that there are no existing discussions - open or closed - to which I could contribute my information.
• I have read the FAQs inside the app (Menu -> About -> FAQs) and my problem isn't listed.
• I have taken the time to fill in all the required details. I understand that the request will be dismissed otherwise.
• This issue contains only one feature request.
• I have read and understood the contribution guidelines.

Feature description

The file manager reads media files (image & video) to generate and display thumbnails. Please allow disabling the feature in the settings.

Why do you want this feature?

Creating the thumbnail images adds overhead, which can slow down lower-end devices in particular. Browsing larger picture folders (thousands of files) likely has a noticeable performance impact on all hardware.

Also has some effect on privacy, since shoulder surfers and such can see the user's pictures (and a frame from videos).

Additional information

No response