Minor improvements to Lua's render lib * Prevent potential issues/minor memory leaks due to Lua errors in some functions (render.DrawQuadEasy, render.DrawScreenQuad, render.PushCustomClipPlan) * Change render.DrawQuadEasy to use better optional argument handling (potentially breaking if mods do silly things) Minor cleanups Added render.GetFogMaxDensity Added a self-check to CBaseHandle::Init Fixed 2 minor compile warnings Defer OnRequestFullUpdate if not in main thread GHA/Steamworks prepwork for network_test branch Fixed potential nullptr server crashes in networking Minor cleanup/compile warning fix Fixed a potential issue with bad BSP embedded files asset:// supports .svg Reject non texture customization files Win32 unicode file search support (disabled) file.Open will block any of those characters anyway, so this was a waste of time, but just throwing this in, in case its useful in the future