Add new setting modeling.highlightEdges (#2166)

* Add doc comment to getThemeColorForEngine

* Add a user-level setting for highlightEdges

* Add a custom settings action to update the edge line visibility

* Make the settings pane always open to user settings first

* Refactor engineConnectionMananer.start() to take a settings object

* Revert alway open user settings

* Set highlight edges on engine start up

* fmt fml

* Fix tsc error

src/machines/settingsMachine.ts

@@ -62,6 +62,17 @@ export const settingsMachine = createMachine(
             ],
           },
 
+          'set.modeling.highlightEdges': {
+            target: 'idle',
+            internal: true,
+            actions: [
+              'setSettingAtLevel',
+              'toastSuccess',
+              'setEngineEdges',
+              'persistSettings',
+            ],
+          },
+
           'Reset settings': {
             target: 'idle',
             internal: true,