[Problem] Ability to embed files in .FCStd / Create packaged file with references.

### Is there an existing issue for this?

- [X] I have searched the existing issues

### Problem description

From the FreeCAD Day 2024 Complaint Session:
**Files contain information specific to the computer they were made on**
Currently all related/embedded files are referenced with absolute paths. If you share your files it shows how the files are structured on the disk they were made on (security concern). So files contain information that is specific to the computer that they were made on.

**Images used as references are not contained in the part**
I think that happens with images too. It is not possible to share an image file together and have it reference inside the FCStd. So images that are used as reference or something else are not contained in the file.

Maybe it is possible to embed referenced files or create a kind of *FCStd package* which packs all used references (images, fonts, linked files) and changes all links to the relative paths of this package file.

A feature like that is present in many applications, e.g. Blender: https://docs.blender.org/manual/en/latest/files/blend/packed_data.html which packs all related data into the main file.
Another option would be to package files like in Adobe InDesign which copies all related images, fonts and referenced files to a folder next to the file (https://creativecloud.adobe.com/en-x-AFRICA/learn/indesign/web/save-share-projects)

### Full version info

```shell
OS: Windows 11 build 22631
Word size of FreeCAD: 64-bit
Version: 0.22.0dev.36277 (Git)
Build type: Release
Branch: main
Hash: 9e1903d46112b3660bf10c6a4537d728101d560b
Python 3.10.13, Qt 5.15.8, Coin 4.0.2, Vtk 9.2.6, OCC 7.6.3
Locale: German/Germany (de_DE)
Installed mods:
* 3DfindIT 1.2.0
* BIM 2021.12.0
* CfdOF 1.25.2
* CurvedShapes 1.0.5
* Curves 0.6.23
* Defeaturing 1.2.2
* fasteners 0.5.12
* FEMbyGEN 2.1.0
* freecad.gears 1.2.0
* freecad_metal_workbench 0.0.1
* OpenDark 2023.12.17
* sheetmetal 0.4.2
```

### Subproject(s) affected?

Core

### Anything else?

Related:
- https://github.com/FreeCAD/FreeCAD/issues/5746
- https://github.com/FreeCAD/FreeCAD/issues/10902

### Code of Conduct

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