testing/electron-tasje, testing/insomnia: new aports

Insomnia is an API client (postman alternative) maintained by Kong, more: https://insomnia.rest/. electron_tasje is my experiment on replacing electron-builder, for a variety of reasons such as downloading electron builds that we don't use, or downloading electron node headers even though we have our own ones in electron-dev, a bit more: https://codeberg.org/selfisekai/electron_tasje/.