Remove symlinks in bundles

[adamwolf]

Based on discussion in https://bugs.launchpad.net/kicad/+bug/1826649 , I'm going to be pulling out symlinks. It'll help enable notarization and signing. It'll reduce complexity in switching to python 3 and in the CMake build process. It will also dramatically reduce the barrier to new developers learning how the macOS build gets packaged. Lastly, and pretty importantly, it'll help user experience in a few key ways--Gatekeeper and not having to open KiCad.app first come to mind.