Simple but imperfect fix for xray candidates race causing /explore to not show sample dataset candidates

Fixes #7241

* let's paint in a happy little loader

* this is what progress looks like

* remove overflow hidden

* clean up progress bar - wip

* usage examples

* fix animation and cleanup other uses

* replace delay with eventually

* make sure to update references

* align titles with cards. fix auto dash wrapper alignment

* pl0

This reverts commit 705d3d04.