UI: Cosmetic changes to "Global Transform" sidebar panel

Cosmetic changes to "Global Transform" panel in 3D Viewport sidebar, to make it
more aligned with rest of the Blender UI.

Note that this isn't a comprehensive update, there are still many things to change
according to our discussions in #137280. This PR only includes small,
non-controversial changes so that we can land improvements in 5.0.
Bigger changes will follow in the next version(s).

List of changes:
- Close all subpanels by default.
- Move "Fix to Camera" subpanel to the bottom, so that it's not between related
"Mirror" and "Relative" subpanels.
- Follow Blender's GUI guidelines:
	- Use `property_split`.
	- Align related properties.
- Remove redundant label from "Relative" subpanel. The title of the subpanel
already communicates the purpose.
- Rename "Mirror Options" subpanel title to just "Mirror". It's obvious that the
panel will contain options.

Pull Request: https://projects.blender.org/blender/blender/pulls/147436

scripts/startup/bl_ui/space_view3d_sidebar.py

@@ -58,6 +58,7 @@ class VIEW3D_PT_copy_global_transform(GlobalTransformPanelMixin, Panel):
 class VIEW3D_PT_copy_global_transform_fix_to_camera(GlobalTransformPanelMixin, Panel):
     bl_label = "Fix to Camera"
     bl_parent_id = "VIEW3D_PT_copy_global_transform"
+    bl_options = {'DEFAULT_CLOSED'}
 
     def draw(self, context: Context) -> None:
         layout = self.layout
@@ -89,23 +90,29 @@ class VIEW3D_PT_copy_global_transform_fix_to_camera(GlobalTransformPanelMixin, P
 
 
 class VIEW3D_PT_copy_global_transform_mirror(GlobalTransformPanelMixin, Panel):
-    bl_label = "Mirror Options"
+    bl_label = "Mirror"
     bl_parent_id = "VIEW3D_PT_copy_global_transform"
+    bl_options = {'DEFAULT_CLOSED'}
 
     def draw(self, context: Context) -> None:
         layout = self.layout
+        layout.use_property_split = True
+        layout.use_property_decorate = False
+
         scene = context.scene
-        layout.prop(scene.tool_settings, "anim_mirror_object", text="Object")
+
+        col = layout.column(align=True)
+        col.prop(scene.tool_settings, "anim_mirror_object", text="Object")
 
         mirror_ob = scene.tool_settings.anim_mirror_object
         if mirror_ob is None:
             # No explicit mirror object means "the current armature", so then the bone name should be editable.
             if context.object and context.object.type == 'ARMATURE':
-                self._bone_search(layout, scene, context.object)
+                self._bone_search(col, scene, context.object)
             else:
                 self._bone_entry(layout, scene)
         elif mirror_ob.type == 'ARMATURE':
-            self._bone_search(layout, scene, mirror_ob)
+            self._bone_search(col, scene, mirror_ob)
 
     def _bone_search(self, layout: UILayout, scene: bpy.types.Scene, armature_ob: bpy.types.Object) -> None:
         """Search within the bones of the given armature."""
@@ -127,15 +134,18 @@ class VIEW3D_PT_copy_global_transform_mirror(GlobalTransformPanelMixin, Panel):
 class VIEW3D_PT_copy_global_transform_relative(GlobalTransformPanelMixin, Panel):
     bl_label = "Relative"
     bl_parent_id = "VIEW3D_PT_copy_global_transform"
+    bl_options = {'DEFAULT_CLOSED'}
 
     def draw(self, context: Context) -> None:
         layout = self.layout
+        layout.use_property_split = True
+        layout.use_property_decorate = False
+
         scene = context.scene
 
         # Copy/Paste relative to some object:
         copy_paste_sub = layout.column(align=False)
         has_relative_ob = bool(get_relative_ob(context))
-        copy_paste_sub.label(text="Work Relative to some Object")
         copy_paste_sub.prop(scene.tool_settings, 'anim_relative_object', text="Object")
         if not scene.tool_settings.anim_relative_object:
             copy_paste_sub.label(text="Using Active Scene Camera")
@@ -162,8 +172,8 @@ class VIEW3D_PT_copy_global_transform_relative(GlobalTransformPanelMixin, Panel)
 classes = (
     VIEW3D_PT_copy_global_transform,
     VIEW3D_PT_copy_global_transform_mirror,
-    VIEW3D_PT_copy_global_transform_fix_to_camera,
     VIEW3D_PT_copy_global_transform_relative,
+    VIEW3D_PT_copy_global_transform_fix_to_camera,
 )
 
 if __name__ == "__main__":  # only for live edit.