fix: resolve VTable issues 5215 5211 5150

[fangsmile]

Summary

• Fix [Feature] 右键菜单插件（@visactor/vtable-plugins 中的 ContextMenuPlugin）不能在整个画布中触发 #5215: support ContextMenuPlugin on canvas blank area via contextMenuWorkOnlyCell=false and CONTEXTMENU_CANVAS handling.
• Fix [Feature] ListTabe树形结构能不能提供清除某一个field的所有勾选状态的方法 #5211: add ListTable checkbox APIs setCellCheckboxStateByRecordIndex, clearCheckboxState, and clearAllCheckboxState for collapsed tree records.
• Fix [Bug] vue模式下的group组件开启了:vue="{}" 的自定义渲染标签后，内部接收到的数据在排序后不会发生变化 #5150: refresh Vue custom layout DOM vnode content after sort/reorder when reusing DOM containers.
• Add dedicated demos for all three issues and add API docs/change files.

Commits

• eecff83 fix: support context menu on canvas blank area
• c5f2114 fix: support checkbox state by record index
• 1c6ffca fix: refresh vue custom layout after sort

Validation

• PASS: packages/vtable-plugins rushx compile
• PASS: packages/vue-vtable rushx compile
• BLOCKED: packages/vtable rushx compile and focused Jest are blocked on current develop vrender export/type issues, e.g. @visactor/vrender-core/entries/runtime-installer, ILegacyBindingContext, ServiceIdentifier, and @visactor/vrender-kits env/installers exports.
• BLOCKED: browser demo runtime loading is blocked by the same Vite dynamic import 500 from vrender/vrender-kits export mismatch; menu entries for the new demos are visible.

Fixes #5215
Fixes #5211
Fixes #5150

[fangsmile]

Closing this combined PR because the fixes have been split into separate branches and PRs per issue: #5247 for #5215, #5248 for #5211, and #5249 for #5150.