Preview spheres for 360 images (#687)

* Preview spheres for 360 images

* Stop the title text wrapping (english/background images tab)

* Single pass support

* Sneak in a Rider package update

* Correctly de-init xr subsystems

* Update Rider plugin

* UNITY_SETUP_STEREO_EYE_INDEX_POST_VERTEX

* Tweak m_ZAdjustHover so labels don't overlap spheres

* Formatting

* Use local normal instead of world normal for far texture on 360 previews

* Fix Advanced Tools panel initial position

* See if rotating the preview spheres fixes the quest shader bug (!?)

Assets/Materials/360 Panorama Sphere.mat

@@ -0,0 +1,89 @@
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