Support GenServer.ex & Supervisor.ex

[petermm]

Carbon copy from upstream, and adapted to gen_server.erl

The GenServerTest and SupervisorTest will go into their own test_exatomvm lib and be included that way - they are included here to highlight this Invalid filename: expected filename data error:

➜  build git:(genserver.ex) ✗ ./src/AtomVM ./tests/libs/exavmlib/Tests.avm
Running Elixir tests
Unable to open Elixir.Enumerable.Tuple.beam
Failed load module: Elixir.Enumerable.Tuple.beam
Unable to open undef.beam
Failed load module: undef.beam
Warning: module undef cannot be resolved.
Invalid filename: expected filename data (27008 bytes).
Invalid filename: expected filename data (27008 bytes).
Invalid filename: expected filename data (27008 bytes).
Invalid filename: expected filename data (18719 bytes).
Finished Elixir tests
Return value: ok

Will stay in draft pending disterl merging and adaption to those changes/features.

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

[petermm]

demo running circuits_i2c with AtomVM_backend https://github.com/petermm/circuits_i2c