App connectivity issues

[ArthurVoxowl]

This issue is compounding because of,

• [ ] frequent world loading failures
  • [ ] even w/ a good internet connection (Windows)
  • [ ] bad app behavior on low-connectivity (all platforms)
• [ ] "Loading..." screen having no way of canceling, meaning the only option is to restart the app
• [ ] the requirement to load the world twice to access it outside the WE, in "dev" mode

Unclear whether it is a different bug or not, but if the second loading fails, when hitting "Play" button in WE, then the app goes back to the main menu, stuck on a loading screen

[ArthurVoxowl]

Related to https://github.com/voxowl/particubes-private/issues/4798