[Feature Request]: Support proxy setting in preferences

In some regions (e.g. China) electron cannot be downloaded due to "network" problems.

Although this can be resolved temporarily with `ELECTRON_MIRROR` or `ELECTRON_GET_USE_PROXY`, but the developer experience is very poor. Meanwhile `ELECTRON_GET_USE_PROXY` not working, for more details see: https://github.com/electron/get/pull/214

It would be helpful for most Chinese developers if we could add a proxy setting to preferences.

Related issues: https://github.com/electron/fiddle/issues/258 https://github.com/electron/fiddle/issues/270

### Obstructed

- [x] https://github.com/electron/get/pull/214
- [ ] `@electron/get` support porxy params in download function
- [x] `@electron/get` removal of support for nodejs versions below 10 (https://github.com/electron/get/pull/214#discussion_r804004094) (Uncertainty)
- [x] `@electron/get` release new verison