S74448: tldr: We fixed legit gui test issues that were not caught in On Demand. I heard you like Reverts, so "Revert "Revert "Revert "Revert "Revert "Revert "S74448: [Milestones] Updated Plan->Milestones page to treegrid"""""""

This reverts commit f3d73445c5b293df3d9af625c754e6e6d7db24d7.