Introduced in 24d08e0bae
The above commit introduced a new batch for drawing UVs in the Image
editor that does not consider face selection when drawing the
corresponding UV map. This was done to reuse the IBO used in object
mode.
Unfortunately, this change didn't account for the case of being able to
select faces in the 3D Viewport (i.e. in Edit or Texture Paint mode)
while also viewing the Image Editor in Paint Mode.
To fix this, the following changes have been made:
* Introduce a new case when drawing the `MeshUV` overlay for objects
being edited.
* Add two new IBO types and a new batch type to clearly differentiate
between the above cases when extracting mesh data.
* Fixes some incorrect usage of the `sync_selection` concept
Pull Request: https://projects.blender.org/blender/blender/pulls/144105
e02eb13a59