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/settingsUtils.ts

@@ -48,6 +48,7 @@ function configurationToSettingsPayload(
       ),
       highlightEdges: configuration?.settings?.modeling?.highlight_edges,
       showDebugPanel: configuration?.settings?.modeling?.show_debug_panel,
+      showScaleGrid: configuration?.settings?.modeling?.show_scale_grid,
     },
     textEditor: {
       textWrapping: configuration?.settings?.text_editor?.text_wrapping,