Fix zero size crash

[terrorfisch]

Fixes #274

💻 Examples

Minimize the window or resize it to y==0. This previously crashed the demo.

✔️ PR Todo

• [x] The are several todo!s remaining that are not handled yet because I do not understand if these cases can occure at all. It feels like failable projection inversion is only a crutch.
• [x] Is the optional WindowSize member of Surface the way to go to represent a minimized/non-existing render target
• [ ] Is skipping the upload system correct when the view is invalid?
• [ ] Check if expect messages meet the desired format.