Reworked ide watch and ide start commands

[mwu-tow]

Pull Request Description

This PR changes build script's ide watch and ide start commands, so they don't use electron-builder to package. Instead, they invoke electron directly, significantly reducing time overhead.

ide watch will now start Electron process, while continuously rebuilding gui and the client in the background. Changes can be puilled by reloading within the electron, or closing the electron and letting it start once again. To stop, the script should be interrupted with Ctrl+C.

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.

[wdanilo]

This is so amazing!!!