install: updates to support building deb/rpm packages that contain python wheels and install core from a single file, updates to core to install scripts by way of python directly

package/after-install.sh

@@ -0,0 +1,16 @@
+#!/bin/sh
+if [ ! -z "${NO_PYTHON}" ]; then
+  exit 0
+fi
+
+PYTHON="${PYTHON:=python3}"
+if [ ! -z "${NO_VENV}" ]; then
+  ${PYTHON} -m pip install /opt/core/core-*.whl
+  echo "DAEMON=/usr/local/bin/core-daemon" > /opt/core/service
+else
+  ${PYTHON} -m venv /opt/core/venv
+  . /opt/core/venv/bin/activate
+  pip install --upgrade pip
+  pip install /opt/core/core-*.whl
+  echo "DAEMON=/opt/core/venv/bin/core-daemon" > /opt/core/service
+fi