Add setting to toggle scale grid visibility (#2838)

* Add a setting for showScaleGrid

* Fix up setting persistence, move under modeling

* Make the setting actually do something

* the lamest fmt I've seen in a while

* Fix clippy warnings

* Add snapshot tests for grid (first time using Playwright masks)

* A snapshot a day keeps the bugs away! 📷🐛 (OS: ubuntu)

* Re-run CI after new screenshots added

---------

Co-authored-by: Jess Frazelle <jessfraz@users.noreply.github.com>
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

src/hooks/useSetupEngineManager.ts

@@ -13,11 +13,13 @@ export function useSetupEngineManager(
     theme: Themes.System,
     highlightEdges: true,
     enableSSAO: true,
+    showScaleGrid: false,
   } as {
     pool: string | null
     theme: Themes
     highlightEdges: boolean
     enableSSAO: boolean
+    showScaleGrid: boolean
   }
 ) {
   const {