Remove workspace object mode, reverts changes w/ 2.8

This caused too many problems syncing object modes
with multiple objects/windows/workspaces, see: D3130 for details.

release/scripts/startup/bl_operators/uvcalc_lightmap.py

@@ -558,8 +558,8 @@ def lightmap_uvpack(meshes,
 
 
 def unwrap(operator, context, **kwargs):
-    workspace = context.workspace
-    is_editmode = (workspace.object_mode == 'EDIT')
+
+    is_editmode = (context.object.mode == 'EDIT')
     if is_editmode:
         bpy.ops.object.mode_set(mode='OBJECT', toggle=False)