Improve Launcher

Things that should be implemented before the initial release:
* [ ] Decide if to separate client download in a different section, or if to download it at the same time as the server
* [ ] Make errors and loading screens actual popups
* [ ] Add settings system
* [ ] Handle some USB and ADB issues (regarding permissions)
* [ ] Add option to not close launcher when server starts
* [ ] Show release notes for each release (preferably correctly formatted with markdown)

Things that can be implemented after the initial release:
* [ ] Add PhoneVR and visionOS downloads and install.
* [ ] Reintroduce server auto-updater (note: self updater should not be needed)