BIM/Draft: display of coordinates for objects with a base object is FUNDAMENTALLY incorrect

### Problem description

First, I'd like to describe the situation with the PART/PARTDESIGN workbenches.
The object relationships there take into account global positioning and relative coordinates (relative to the attachment). See the image.


But in the BIM and DRAFT workbenches, all child objects show ONLY global coordinates (attachments are not implied by default).
What does this mean? It means that objects display zero coordinates even if the object is offset. This happens because the true coordinate is not assigned to the base object.

This is an important feature that takes some getting used to. And I can tell you that it is very, very unclear to new users.
It would be much more correct to display the true coordinates in the properties. Or at least mark them as attachment coordinates (similar to PART/PART DESIGN). Because, in fact, it's attached to the base object.

sketch-base:

Object


Furthermore, the current solution causes displacement summation if we move both the base and the object itself in the 3D window. The objects EXPLODE, and they fly apart. https://github.com/FreeCAD/FreeCAD/issues/16278

But the best solution would be to establish a relationship between the child and parent objects.
The concept is shown in the picture.


File For Test

[Coordinates.FCStd.remove.zip](https://github.com/user-attachments/files/26110636/Coordinates.FCStd.remove.zip)

### Workbench affected?

BIM

### Steps to reproduce

---

### Expected behavior

---

### Actual behavior

---

### Development version About Info (in Safe Mode)

```shell
any versions
```

### Last known good version (optional)

```shell
---
```

Open the attached Coordinates.FCStd file and reproduce the coordinate display and displacement behavior in the BIM and Draft workbenches. Compare the child and base-object behavior with Part/PartDesign, then define completion as showing meaningful attachment coordinates and preventing parent and child movement from causing objects to separate.

Written by the indexing model from the issue text.