v2.8 "Import/Export" and v2.9 (minor hotfix)

We forgot to post news about 2.8 a couple of months ago. v2.9 was just released and fixed a small bug that only affected the Quest version so I'll post the belated 2.8 news instead! [h1]๐Ÿš€ Features[/h1] [list] [*] Remove almost all uses of Experimental Mode, and combine Monoscopic into the main releases (PR #674 by @andybak) [*] Skip intro tutorial on Zapbox (PR #681 by @mikeskydev) [*] Allow generation of sphere with gesture on mobile (PR #678 by @mikeskydev) [*] Update lots of shaders to singlepass (PR #677 by @mikeskydev) [*] Preview spheres for 360 images (PR #687 by @andybak) [*] Pagination for layers UI (PR #698 by @andybak) [*] Folder navigation UI (PR #689 by @andybak) [*] Import/export improvements (PR #573 by @andybak) [*] Passthrough Hull Brush (PR #613 by @andybak) [*] UnityGLTF Shader Variants (PR #714 by @andybak) [*] Add Pico support to the generic OpenXR build (PR #719 by @mikeskydev) [*] Disable boundary when passthrough is active (PR #735 by @andybak) [/list] [h1]๐ŸŽจ UI / UX[/h1] [list] [*] Fix Advanced Tools panel initial position (PR #697 by @andybak) [*] Damn panel spacing (PR #702 by @andybak) [/list] [h1]๐Ÿ› Fixes[/h1] [list] [*] Fix broken multimirror options popup. Hide Tiltosaurus button as it dโ€ฆ (PR #680 by @andybak) [*] Workaround for PCVR depth submission (PR #685 by @mikeskydev) [*] De-initialize XR Subsytems properly (PR #695 by @andybak) [*] Background image preview sphere labels (PR #700 by @andybak) [*] Fix stereo pano sphere preview (PR #701 by @andybak) [*] Enable file system watcher on mobile (PR #704 by @andybak) [*] UnityGltf import is meant to default to off (PR #707 by @andybak) [*] Fix issue where transparent brushes were invisible in Quest passthrough mode. (PR #715 by @andybak) [*] m_ColorSaturationMax had accidentally been set to 0 breaking color picker (PR #724 by @andybak) [*] Fix issue where images that are too large fail to load without any inโ€ฆ (PR #722 by @eeropomell) [*] Fix/improve image loading (PR #729 by @eeropomell) [*] Fix/quest sdk no boundary (PR #737 by @andybak) [*] Rename Quest Boundary Property (PR #739 by @andybak) [*] Fix input system errors when running in the editor (PR #745 by @andybak) [*] Shift the preview down so it doesn't overlap the hint (PR #750 by @andybak) [*] Fix background image seams by bypassing cache for now (PR #749 by @andybak) [/list]