UI: Shape key right click context menu

Invoke context menu for shape key with right click.
Added `MESH_MT_shape_key_tree_context_menu`, this include operators
that takes action on selected/active tree items:
- Make Basis
- Duplicate
- Move to Top -> Move After Basis
- Move to Bottom -> Move to Last

See Video in PR description

Pull Request: https://projects.blender.org/blender/blender/pulls/143444

scripts/startup/bl_ui/properties_data_mesh.py

@@ -84,6 +84,18 @@ class MESH_MT_shape_key_context_menu(Menu):
         layout.operator("object.shape_key_move", icon='TRIA_DOWN_BAR', text="Move to Bottom").type = 'BOTTOM'
 
 
+class MESH_MT_shape_key_tree_context_menu(Menu):
+    bl_label = "Shape Key context menu"
+
+    def draw(self, _context):
+        layout = self.layout
+        layout.operator("object.shape_key_make_basis", text="Make Basis")
+        layout.operator("object.shape_key_copy", icon='DUPLICATE', text="Duplicate")
+        layout.separator()
+        layout.operator("object.shape_key_move", icon='TRIA_UP_BAR', text="Move After Basis").type = 'TOP'
+        layout.operator("object.shape_key_move", icon='TRIA_DOWN_BAR', text="Move to Last").type = 'BOTTOM'
+
+
 class MESH_MT_color_attribute_context_menu(Menu):
     bl_label = "Color Attribute Specials"
 
@@ -690,6 +702,7 @@ class DATA_PT_vertex_colors(MeshButtonsPanel, Panel):
 classes = (
     MESH_MT_vertex_group_context_menu,
     MESH_MT_shape_key_context_menu,
+    MESH_MT_shape_key_tree_context_menu,
     MESH_MT_color_attribute_context_menu,
     MESH_MT_attribute_context_menu,
     MESH_UL_vgroups,

source/blender/editors/object/interface_template_shape_key_tree.cc

@@ -230,6 +230,15 @@ class ShapeKeyItem : public ui::AbstractTreeViewItem {
     return label_;
   }
 
+  void build_context_menu(bContext &C, uiLayout &layout) const override
+  {
+    MenuType *mt = WM_menutype_find("MESH_MT_shape_key_tree_context_menu", true);
+    if (!mt) {
+      return;
+    }
+    UI_menutype_draw(&C, mt, &layout);
+  }
+
   std::unique_ptr<ui::AbstractViewItemDragController> create_drag_controller() const override
   {
     return std::make_unique<ShapeKeyDragController>(