Using Duplicate To for folders in the filesystem dock may cause unexpected behavior

[Rindbee]

Godot version

v4.2.dev4.official [549fcce]

System information

Godot v4.2.dev4 - Linux Mint 21.2 (Victoria) - X11 - Vulkan (Forward+) - dedicated NVIDIA GeForce GTX 1050 Ti (nvidia; 535.86.05) - Intel(R) Core(TM) i5-7300HQ CPU @ 2.50GHz (4 Threads)

Issue description

Select a folder A in the FileSystem dock, right-click to open the context menu, select Move/Duplicate To..., select another folder B in the popup dialog, and check Copy File(s) , click the Copy button to copy:

1. if A is an empty directory, duplication has no effect.
2. If B already contains A, trying the Keep Both option will result in a path like B/A (2)/A/.

Peek.2023-09-08.07-55.mp4

The second case above also applies to Move To.

Peek.2023-09-08.08-39.mp4

Steps to reproduce

See above.

Minimal reproduction project

N/A