Changed: Make Viewer more responsive during login inventory skeleton creation, show progress to the user.

Cleanup. Caused by a merge of main(D567) into D559

SL-20450: Fix missing LSL keyword INVENTORY_MATERIAL

SL-20440 Fix for projector ambiance destroying PBR shading.  Also fix longstanding bug with hard line in projector ambiance lighting.  Incidental decruft of legacy_adjust and LOCAL_LIGHT_KILL, etc.

SL-20396: Apply blinn-phong rotation to texture translation animations for GLTF materials

There is no asset capability during teleport and it can take some time
to arrive, texture shouldn't just fail to fetch if capability arrives
after content.

SL-20225: Update LLGLTFMaterial

Fixed: Several error notifications that notification X couldn't be found such as when trying to create a subfolder.

Added: Descriptions to all new PBR options in preferences.
Added: Reflection Probe Draw Distance option.
Added: Reflection Probe Ambiance weight option.
Added: Reflection Probe Light weight option.
Added: Reflection Probe Resolution option.
Fixed: Reflection Detail options using the wrong values.

Changed: Completely overhauled all of the tools window except Texture tab which needs some figuring out.