Can't dock undocked window

### Is there an existing issue for this?

- [x] I have searched the existing issues

### Problem description

If I have two open documents and I undock one of them using _Main Menu > View > Document Window > Undocked_ , I can't dock that window because the main menu action only applies to the other, docked window. However, I can use the shortcut VD to dock it.

I would also suggest to change the shortcuts: As now, there are seperate shortcuts for docking (VD) and undocking (VU), it would be better to only have one (i.e. VD) that toggles the mode!

### Full version info

```shell
OS: Windows 11 build 26200
Architecture: x86_64
Version: 1.1.0dev.44097 (Git)
Build date: 2025/11/02 16:03:37
Build type: Release
Branch: main
Hash: 45ca23d074f39a9b586c8320f1e7cd20ca466fef
Python 3.11.13, Qt 6.8.3, Coin 4.0.3, Vtk 9.3.0, boost 1_84, Eigen3 3.4.0, PySide 6.8.3
shiboken 6.8.3, xerces-c 3.3.0, IfcOpenShell 0.0.0, OCC 7.8.1
Locale: English/United States (en_US)
Navigation Style/Orbit Style/Rotation Mode: Touchpad/Turntable/Object center
Stylesheet/Theme/QtStyle: OpenDark.qss/OpenDark/
Logical DPI/Physical DPI/Pixel Ratio: 96/126.047/1.5
Installed mods:
* Curves 0.6.70
* fasteners 0.5.43
* fasteners-backup-before-zip-migration 0.5.41 (Disabled)
* freecad.gears 1.3.0
* freecad.gears-backup-before-zip-migration 1.3.0 (Disabled)
* IconThemes
* OpenTheme 2025.5.20
* OpenTheme-backup-before-zip-migration 2025.5.20 (Disabled)
* sheetmetal 0.7.55
```

### Subproject(s) affected?

None

### Anything else?

_No response_

### Code of Conduct

- [x] I agree to follow this project's Code of Conduct