Scrolling mods paints them one by one

[MCW77]

Description:

Scrolling mods in the explorer paints the mods one by one when they enter the view.

Current implemementation of RenderIfVisible creates an intersection observer for every wrapped ModDetail. By adding the feature of using a shared observer to RenderIfVisible we should be able to handle several mods that intersect the root at once.

Steps to reproduce the issue:

• Go to the mod explorer
• Scroll the mods fast enough so that a bunch get into view at the same time
• Observe how each mod that scrolled into view is painted one after the other

Expected behavior:

All mods getting into view start painting at the same time

Actual behavior:

Mods scrolling into view paint one after the other

@pawee Checkout my fork of the optimizer. By virtualizing the mods entering the mod explorer is instant, also filtering mods. Once i resolve the two issues i currently have with the intersection observer, the scrolling should be fast too. You can test my fork at mods-manager.pages.dev

[pawee]

I'm trying to check this out but I can't find the fetch data button when opening in mobile browser.

[MCW77]

You don't need it for the first fetch and it will be there after you entered your allycode and thus triggered the first fetch.