Ease debugging, fix some CI issues, tweak folder structure (#200)

* Enable debug for OTP versions' listings

* Make it easier to detect

* Prevent error annotation on expected error

The fact that one mirror fails in the above test and others follow
working is test enough for me

A single failing mirror should fail, but it's confusing to have
an error annotation for a success (via continue-on-error) while
not being able to suppress it via GitHub Actions

* Trying to figure out why we have a rebar_core exception

Might simply be that the bug is already fixed and we need to bump rebar3

* Try to debug into non-JSON input

* Prevent error in rebar_core

We're getting Access Denied for
Fetching registry from "https://repo.hex.pm:443/registry.ets.gz?"

* Try to figure out what's breaking tests

* Make jsonParse(...).map failure more understandable

* Ease test maintenance

* Tweak folder structure while moving console._ to core._

test/projects/erlang_rebar3/src/mylib.app.src

@@ -0,0 +1,16 @@
+{application, mylib, [
+    {description, "An OTP library"},
+    {vsn, "0.1.0"},
+    {registered, []},
+    {mod, nil},
+
+    {applications, [
+        % OTP dependencies
+        kernel,
+        stdlib
+    ]},
+
+    {env,[]},
+
+    {licenses, ["Apache 2.0"]}
+ ]}.

test/projects/erlang_rebar3/src/mylib.erl

@@ -0,0 +1,17 @@
+%%%-------------------------------------------------------------------
+%% @doc mylib public API
+%% @end
+%%%-------------------------------------------------------------------
+
+-module(mylib).
+
+-export([hello/0]).
+-ignore_xref(hello/0).
+
+-spec hello() -> world.
+hello() ->
+    Ret = world,
+    _ = io:format("~p", [Ret]),
+    Ret.
+
+%% internal functions