Update nodes auto layout spacing for snap to grid size

Update workflowSettingsSlice.ts

Change the default settings for auto layout nodeSpacing and layerSpacing  to 30 instead of 32.    This will make the x position of auto layed nodes land on the snap to grid positions. 

Because the node width (320) + 30 = 350 which is divisible by the snap to grid size of 25.

Author: skunkworxdark

invokeai/frontend/web/src/features/nodes/store/workflowSettingsSlice.ts

@@ -33,8 +33,8 @@ const initialState: WorkflowSettingsState = {
   _version: 1,
   shouldShowMinimapPanel: true,
   layeringStrategy: 'network-simplex',
-  nodeSpacing: 32,
-  layerSpacing: 32,
+  nodeSpacing: 30,
+  layerSpacing: 30,
   layoutDirection: 'LR',
   nodeAlignment: 'UL',
   shouldValidateGraph: true,