Use atomvm_packbeam instead of built-in C packbeam

[pguyot]

Kept the remove lines for release avm builds.
Install packbeam escript as bin/packbeam

Obsoletes #1429
Requires atomvm/atomvm_packbeam#47

Adding -p for runnable would be a good thing but requires atomvm/atomvm_packbeam#60

These changes are made under both the "Apache 2.0" and the "GNU Lesser General
Public License 2.1 or later" license terms (dual license).

SPDX-License-Identifier: Apache-2.0 OR LGPL-2.1-or-later

[UncleGrumpy]

This is a nice improvement, and should simply maintenance - focusing our efforts on a single implementation of packbeam.

This should probably include a mention that it supersedes #1429.

[bettio]

I agree with this change but I think we should vendor here the tool we use for making .avm files. So we can build without any network access and make happy people trying to use Nix.

[UncleGrumpy]

Would including atomvm_packbeam here as a git submodule be enough to keep the nix people happy?
I think it is best kept as a stand alone repo since the atomvm_rebar3_plugin (and maybe eventually ExAtomVM) depend on it as well.