Improve handling of rendering startup errors

[RandomShaper]

Makes RenderingDevice startup fail if staging buffers can't be created. Also allows any error in such initialization to take the engine through the path where it can handle it so it can eventually show the message box that suggests using GL ES 3, etc.

Despite this, the engine still crashes after that (at least in my case and with a dev build). However, this is already a step forward so in cases such as the one in #93670 users get at least some friendly error instead of a plain crash with no further info.