Fix Reorder operation with bassets

[promatik]

This is a simple fix for the reorder operation with bassets.
It now uses the local file, that should be internalized by the new version of bassets (DigitallyHappy/assets#19 should be merged).

Before merging ...

What is the best place to have these custom javascript/styles?
I placed it in src/resources/assets/libs/jquery.mjs.nestedSortable2.js.

1. Should we create a bunch of folders to organize everything or throw them all in that folder? js/css folders or libs or anything else?

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2. Did we have more custom files besides nestedSortable2?

[scrutinizer-notifier]

The inspection completed: 90 new issues

[tabacitu]

This is freaking awesome Antonio!

1. For now I think libs will do just fine. If/when we need to add more files, we'll think about it.
2. Not that I know of, no... I think this is the only library file we had overridden. But we'll also probably have OTHER files, like completely custom CSS files. Completely custom JS files. That either Backpack provides... or the theme provides. To rephrase... that either the parent theme provides... or the child theme provides.

I've merged this, we're good now. Phiew!!!

[tabacitu]

PS. The beauty of @basset() is that it allows us, maintainers, to move the JS file in a different directory... and it'd be a non-breaking change. That is freaking great! 😀