RNA: Object.select_set use boolean, only select

- Was setting active state, making it necessary to backup/restore
  active object in cases where this isn't needed.
  Existing scripts are explicitly setting the active object when needed.

- Use a boolean select arg (toggle selection wasn't used anywhere).

- Add an optional view layer argument since scripts should be able to
  operate outside the user context.

release/scripts/templates_py/batch_export.py

@@ -18,7 +18,7 @@ bpy.ops.object.select_all(action='DESELECT')
 
 for obj in selection:
 
-    obj.select_set(action='SELECT')
+    obj.select_set(True)
 
     # some exporters only use the active object
     view_layer.objects.active = obj
@@ -31,7 +31,7 @@ for obj in selection:
     # Can be used for multiple formats
     # bpy.ops.export_scene.x3d(filepath=fn + ".x3d", use_selection=True)
 
-    obj.select_set(action='DESELECT')
+    obj.select_set(False)
 
     print("written:", fn)
 
@@ -39,4 +39,4 @@ for obj in selection:
 view_layer.objects.active = obj_active
 
 for obj in selection:
-    obj.select_set(action='SELECT')
+    obj.select_set(True)