Add option to load all thumbnails at startup and don't unload them

[soredake]

Checklist

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

Feature description

It will be nice to have option to load all thumbnails at startup and don't unload them, like in this app https://play.google.com/store/apps/details?id=com.google.android.apps.photosgo

Why do you want this feature?

I love to scroll my images fast, and i don't love seeing them loading on-demand or unloading when i scroll.

Additional information

No response

[Aga-C]

Would this be enough for you: https://github.com/FossifyOrg/Gallery/issues/136?

[soredake]

If disabling this "fade-in" effect will mean that all thumbnails will always be loaded (as startup too), then yes.