Handling exceptions in IDE main to avoid entering "zombie process" state.

[mwu-tow]

Pull Request Description

This is meant to address https://www.pivotaltracker.com/story/show/182691027.

Important Notes

Checklist

Please include the following checklist in your PR:

• The documentation has been updated if necessary.
• All code conforms to the
  Scala,
  Java,
  and
  Rust
  style guides.
• All code has been tested:
  • Unit tests have been written where possible.
  • If GUI codebase was changed: Enso GUI was tested when built using BOTH
    ./run ide build and ./run ide watch.

[MichaelMauderer]

Suggested change

	// It is critical that the main function runs in its entirety. Otherwise, IDE enters a "zombie
	// process" state, where Electron processes have been spawned, but there is no window and user can't
	// observe anything. Usually they will try to spawn another instance of the IDE, but this can fail
	// because of these zombie process presence.
	//
	// The solution is to catch all errors and exit the process if any part of the initial setup fails.
	// If it succeeds, at least the Window will be shown, allowing the user to observe the error and
	// close it.
	// It is critical that the main function runs in its entirety. Otherwise, IDE enters a "zombie
	// process" state, where Electron processes have been spawned, but there is no window and the user can't
	// observe anything. Usually, they will try to spawn another instance of the IDE, but this can fail
	// because of these zombie process presence.
	//
	// The solution is to catch all errors and exit the process if any part of the initial setup fails.
	// If it succeeds, at least the window will be shown, allowing the user to observe the error and
	// close it.