Update Electron

[lidel]

We are at 19.x which is no longer receiving maintenance. Latest one is 29.

• https://www.electronjs.org/docs/latest/tutorial/electron-timelines

There has been a long list of breaking changes between 19 and 29, and some things mentioned there are used in our codebase:

• https://www.electronjs.org/docs/latest/breaking-changes

We need to go over all of them and ensure there are no regressions.