Inconsistency when fetching addons

There are a few inconsistencies when the addon manager (v2026.8.18 and bundled) fetches addons:

- a few of them don't have their icon fetched (the fact that missing icons are grouped may means something)

- An addon is sometimes displayed under it s key name (e.g. from https://github.com/FreeCAD/Addons/blob/main/Data/Index.json#L622-L630), and sometimes using the name defined in package.xml file. It seems random.

Both issues seem correlated: when my addon is displayed as `CarteGrid`, it has an icon; and when it is displayed as `FreeCAD-Params-Export` it does not have a logo.

This leads me to think it has an issue on the server side script that fetches metadata. I will investigate

For reference : https://github.com/MarcBresson/CarteGrid/issues/32 and https://github.com/FreeCAD/Addons/issues/140

Compare the affected entries in the Addons Data/Index.json file with their package.xml metadata, starting with the CarteGrid and FreeCAD-Params-Export examples. Trace the addon manager's metadata-fetching path and check whether icon and display-name results come from the same source. Done means the affected addons consistently show their intended name and icon.

Written by the indexing model from the issue text.