Bake and embed textures from layer stack into GLB export

[ikonnow]

Feature description:
Add the ability to bake and embed textures from the layer stack into GLB export. Currently, meshes can be exported to GLB format, but the textures are not included in the export. The feature should apply all layers from the layer stack (similar to Blender's bake functionality) and embed the resulting textures into the GLB file.

This is different from issue #2008 which focuses on exporting texture paths. This request is about actually baking and embedding the textures into the GLB file.

Why this is needed:

• GLB files without materials/textures are limited in use
• Current knife export works but lacks textures
• Having baked materials in GLB would make the exported models immediately usable in other applications
• Similar to how Blender handles texture baking for GLB export

Proposed implementation:

• Add a checkbox or option in the GLB export dialog: "Bake and embed textures"
• When enabled, bake all layers from the layer stack onto the mesh
• Embed the resulting textures into the GLB file
• This would be similar to the existing bake functionality but specifically for GLB export

[ikonnow]

Additionally, it would be great to have Blender-like material settings

and compression options for GLB export. These settings are available through the Blender plugin. Previously, ArmorPaint had a plugin for GLB import/export, and now this functionality is default enabled. However, without the materials, the export is limited.

[luboslenco]

I have linked the #2008 since the original intent was "In order to properly view your extracted mesh". Will try to implement 3 options for glb export - no materials, material with texture paths, material with embedded textures.