[Feature Request] Dragging for Folder as Workspace should also work when dragging files to editor is on

Description of the Issue

When we turn on option Open all files of folder instead of launching Folder as Workspace on folder dropping (Preferences > Default Directory), we can't load any folder to FaW panel by dragging. I know we have context menu and Add option, but digging in open dialog to select a specific folders is very inconvenient.

Steps to Reproduce the Issue

1. Open NPP.
2. Go to Preferencess > Default Directory and select Open all files of folder instead of launching Folder as Workspace on folder dropping
3. Open Folder as Workspace panel
4. Try to load any folders to Workspace panel by dragging

Expected Behavior

Whe option Open all files of folder instead of launching Folder as Workspace is select then should be some hook to allow load folders in this panel by dragging. It can be done for example by detecting a key pressed (Ctrl, Alt, Shift or other) or make toolbar of this panel draggable (where we have 3 buttons), or make all FaW panel draggable separate to main window, so dragging folders will always work, regardless of some other options.

Actual Behavior

Dragging folders not work.

Debug Information

Notepad++ v7.9.1 (32-bit)
Build time : Dec 21 2020 - 18:20:21
Path : D:_test\NPPClean\notepad++.exe
Admin mode : ON
Local Conf mode : ON
OS Name : Windows 7 Ultimate (64-bit)
OS Build : 7601.0
Current ANSI codepage : 1250
Plugins : none

Reproduce the behavior through Preferences > Default Directory with the Folder as Workspace panel open, then trace the panel's folder drag-and-drop handling and its interaction with the option to open all files. Done means folders can be dragged into Folder as Workspace while that option is enabled, with the existing file-drag behavior preserved.