Part of #69107

Electron no longer publishes binary releases under the arm tag, and requires use of the armv7l tag instead.

As other parts of the build system (and downstream tools) may still be relying on using the "arm" keyword, I've made it so that "armv7l" is passed to gulp-atom-electron without changing the internal code structure.

This reverts commit 02d267c5.

Happy new year! 🎆

This reverts commit 3cfe1739.

* first cut icons per file type (for #4845)

* update icon set

* update distro

* tweaks

* update distro

Adding tasks to allow for explicitly download ARM and ARM64 versions of Electron when it is not the native architecture of the build machine (for cross-compiling).