Experimental Support for Tracking Tools with Passive Spherical Markers

After a couple of different issues were raised about this topic, I tried to add some very quick modifications to enable support for spherical passive markers under the [`experimental`](https://github.com/HL2-DINO/DINO-DLL/tree/experimental) branch of DINO-DLL.

To use the new modifications you should follow these instructions:

### 1) Fetch updates and rebuild DINO-DLL

``` bash
## clone repo if you don't have it already
# git clone https://github.com/HL2-DINO/DINO-DLL
cd DINO-DLL
git fetch
git pull
git checkout experimental
```

- Open the `.sln` file. build for `Release`, `ARM64`.
- Copy your new `HL2DinoPlugin.dll` & `HL2DinoPlugin.winmd` from `DINO-DLL/ARM64/Release/HL2DinoPlugin`
- Paste into the DINO-Unity folder so it's inside `Assets/Plugins/WSA`.

### 2) Modify `DinoToolsConfig.json`

The only change in DINO-Unity required is to modify the `.json` file used to construct your Unity project. For a tracked-tool inside the `tools` array of the file, you can now add a new key-value pair to describe the spherical marker radius.

``` json
{
"fileSettings": {"units" : "m"},
"tools":
[
{
"name": "Stylus",
"id": 8,
"coordinates":
[
["0","0","0"],
["0","0.07","0"],
["0","0.13701","0"],
["-0.03939","0.09175","0"],
["0.04704","0.09216","0"]
],
"marker_radius_m" : 0.0056
}
]
}

```

> [!IMPORTANT]
> This should be the radius of the passive spheres attached to the tool, in _**metres**_.

> [!TIP]
> A radius value of `0` should be used for flat markers. If this field is not specified for a tool in the `.json` file, then the code in `DINO-DLL` will automatically fill this field to be 0.

Rebuild DINO-Unity as instructed in the README (e.g. [see instructions](https://github.com/HL2-DINO/DINO-Unity/tree/unity-21?tab=readme-ov-file#getting-started) for the `unity-21` branch).

---

These changes were made relatively quickly, so please do review the new code in `DINO-DLL` yourself.

Effectively, the main change made is that when trying to associate detected marker-blobs with tools, you iteratively try out different marker radii specified in the `config.json` when trying to compute pose for different tools.

It's certainly considered an experimental and slightly unstable addition, as I haven't been able to robustly test it, and the code logic could be implemented in a more elegant way, so it has not been merged with the main branch just yet. Feedback is welcome!

Start by reviewing the experimental branch changes in DINO-DLL and the DinoToolsConfig.json marker_radius_m example, then follow the README build instructions for DINO-Unity. Done means the spherical-marker support has been reviewed and tested, including the documented zero-radius behavior for flat markers, with the remaining stability concerns addressed.

Written by the indexing model from the issue text.