feat(TreeView): support Darg and Drop function (#6121)

* feat:DraggableTree

* fix:修正格式错误

* 添加TreeView拖拽功能测试

* Enhance TreeView drag-and-drop and add comprehensive tests

Improved TreeView drag-and-drop logic to handle moving nodes without parents and updated node removal accordingly. Added and expanded unit tests to cover moving nodes as last child, first child, and as siblings below, ensuring correct parent/child relationships and node ordering. Also added clarifying comments in TreeViewRow for drag-and-drop preview UI.

* Add draggable TreeView demo with drop restrictions

Introduced a new demo block showcasing draggable TreeView nodes, including logic to restrict certain drag-and-drop operations. Added localized strings for the new demo in both English and Chinese. Updated the backend to provide a sample data set and drop event handler enforcing the restrictions.

* Refactor TreeView drag-and-drop and improve tests

Refactored TreeView and TreeViewRow to require OnItemDrop and remove null checks, simplifying drag-and-drop logic. Updated tests to cover cases where OnItemDrop is not set and to verify drag-and-drop visual feedback.

* refactor: 代码格式化

* refactor: 代码规范化

* refactor: 提高可读性

* refactor: 代码格式化

* Revert "Enhance TreeView drag-and-drop and add comprehensive tests"

This reverts commit 3c8f5a1.

* Revert "Merge branch 'main' into main"

This reverts commit 7ea39da, reversing
changes made to 3c8f5a1.

* Revert "Add draggable TreeView demo with drop restrictions"

This reverts commit 906f2aa.

# Conflicts:
#	src/BootstrapBlazor.Server/Components/Samples/TreeViews.razor
#	src/BootstrapBlazor.Server/Components/Samples/TreeViews.razor.cs

* Revert "Refactor TreeView drag-and-drop and improve tests"

This reverts commit 81235e9.

# Conflicts:
#	src/BootstrapBlazor/Components/TreeView/TreeView.razor.cs

* Revert "添加TreeView拖拽功能测试"

This reverts commit de2be13.

* Revert "feat:DraggableTree"

This reverts commit 8ae8825.

# Conflicts:
#	src/BootstrapBlazor.Server/Components/Samples/TreeViews.razor.cs
#	src/BootstrapBlazor/Components/TreeView/TreeView.razor
#	src/BootstrapBlazor/Components/TreeView/TreeView.razor.cs

* revert: 撤销更改

* revert: 撤销更改

* revert: 撤销更改

* revert: 撤销更改

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Co-Authored-By: Symin <[email protected]>
Co-authored-by: Argo Zhang <[email protected]>

Author: syminomega