Rework integration with the standard GLTF exporter

[kaosat-dev]

Currently, the Blender add-on is doing a few shortcuts when it comes to more advanced export settings. (Ie, the standard Blender Gltf exporter has a whole logic in place for example when you toggle animation export on/off), which could lead to bugs/ unexpected behaviour. There are two main options I see:

• change the auto exporter to integrate into Blender's Gltf exporter : ie add our custom tabs & settings as additional settings inside the standard exporter (did a few basic attempts at this, and it seems feasible on the surface). This would simplify a part our own code, remove the need to re-implement features etc, but might be complicated to do
• copy/paste some of the code from the standard exporter's logic & ui (is an ok stopgap solution, but does not scale at all)