Blender Git Loki

Fix T73069: Studiolights

Studiolights that were just created didn't had the
`STUDIOLIGHT_SPECULAR_HIGHLIGHT_PASS` flag. Without this flag the
studiolight the viewport didn't show the specular highlights and it
wasn't possible to switch the highlights on/off in the popover. After
reloading the studio lights this was possible.

This patch will always set the flag for any newly created, or being
edited studiolight, so the workbench render engine is fed with the right
data.