FBX exporter code was only supporting "Face Corner - Byte Color"
attribute type, using the deprecated Mesh.vertex_colors API. Update
the to use the new attributes API, and to handle all the attribute
combinations.

An option to pick between sRGB (default, matches current behavior),
Linear (requested in T82847) or None (don't export/import any color
attributes) has been added to the exporter and the importer.

Reviewed By: Bastien Montagne
Differential Revision: https://developer.blender.org/D15942

Part of T80730

Small micro optimization

Add more features for Material and ImageTexture settings:
1. The ability to change Interpolation Mode of the texture (linear, closest, cubic, smart).
   Before there was only linear as default.
2. The ability to change the extension parameter.
3. The ability to change a Blend Mode (Blend, Clip, Hashed).
   Before there was only Blend (or Opaque if "Use Alpha" is unchecked) as default.
4. In "Alpha Blend" case, added the "Show Backface" checkbox.
5. The ability to change the Shadow Mode (Clip, Hashed, Opaque) or disable casting shadows.
   Before there was only "Alpha Clip" as default.
6. The ability to enable Backface Culling.

Reworked:
1. Compositing Nodes, Material Settings and Texture Settings are in different layouts now.
2. "Use Alpha" checkbox has moved from "Texture Setting" to "Material Settings".

Differential Revision: https://developer.blender.org/D15744

"Add/Remove nested from selection" was inverting the selection for the
branch instead of adding or removing.  This fixes it to behave similarly
to toggling nested RTOs.

Bring back the auto-generated block delimiters
Also: sort unregister() in reverse order to register()

Revert part of rBAad1966474ed2 in nw_check() which was giving no benefit
afaict (and instead tried to access space.node_tree for Spaces other
than the Node Editor, spamming the console with errors).

Differential Revision: https://developer.blender.org/D15770

glTF exporter: do not bake selected skinned meshes, as glTF transforms must be ignored on skinned meshes

The 3D Print Toolbox addon was using the Python based exporter API,
switch it to use the C++ based obj exporter. This is faster, supports
vertex color attributes, and allows to remove the Python based exporter
some day.

Reviewed By: Campbell Barton
Differential Revision: https://developer.blender.org/D15769

Two operators were missing the option to enable the Undo registering.

A variety of operators were missing appropriate bl_options for correct
undo support.

This results in either crashes (auto loft, bi-rail) or other odd
behaviors around returning the scene to the correct previous state
(sometimes having to hit ctrl-z twice to undo once, sometimes undo skips
steps, etc.)

Differential Revision: https://developer.blender.org/D13283

Add guards to the functions triggered by checkbox updates
in the preferences.  This prevents them from being called
multiple times, such as when the mouse is hovered over
the checkbox and the backspace key is repeatedly pressed.

Contributed by luzpaz.

Differential Revision: https://developer.blender.org/D15646

Unfortunately, messages cannot be properly extracted from f-strings.
Use `str.format()` method instead.

Ref D15615