refactor: reorganize and to end and smoke testing (#348)

1. we can merge the e2eminiooni.yml test into the miniooni.yml test
so to reduce the number of tests we run;

2. ideally we would like the smoketest.sh test to evolve and also
check whether we can fetch the measurements we submitted, so start
moving this script into the `./E2E` folder, add a note saying we
would like to do that, and direct all the tests to run this script
at its new location and with its new name (`ooniprobe.sh`).

With these two changes, it's fine to remove the ooniprobe2debian.yml
test in ooni/e2etesting because we're moving its functionality to this
repository. (We mentioned the need to do this move in a previous TODO
comment at the top of such a script.)

Work part of https://github.com/ooni/probe/issues/1468

E2E/ooniprobe.sh

@@ -0,0 +1,16 @@
+#!/bin/sh
+#
+# This test for now uses --no-collector and we just ensure that the OONI
+# instance is not exploding. We are confident that, if miniooni submits
+# measurements, also ooniprobe should be able to do that. However, it would
+# actually be nice if someone could enhance this script to also make sure
+# that we can actually fetch the measurements we submit.
+#
+set -ex
+if [ "$#" != 1 ]; then
+    echo "Usage: $0 <binary>" 1>&2
+    exit 1
+fi
+$1 onboard --yes
+# Important! DO NOT run performance from CI b/c it will overload m-lab servers
+$1 run websites --config cmd/ooniprobe/testdata/testing-config.json --no-collector