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/lib/settings/initialSettings.tsx

@@ -325,6 +325,18 @@ export function createSettings() {
         },
         hideOnLevel: 'project',
       }),
+      /**
+       * Whether to show a scale grid in the 3D modeling view
+       */
+      showScaleGrid: new Setting<boolean>({
+        defaultValue: false,
+        description: 'Whether to show a scale grid in the 3D modeling view',
+        validate: (v) => typeof v === 'boolean',
+        commandConfig: {
+          inputType: 'boolean',
+        },
+        hideOnLevel: 'project',
+      }),
       /**
        * Whether to show the debug panel, which lets you see
        * various states of the app to aid in development