Add a tag backfill worker to fully backfill the new-style Tag's in the background

conf/init/service/batch/tagbackfillworker/log/run

@@ -0,0 +1,4 @@
+#!/bin/sh
+
+# Start the logger
+exec logger -i -t tagbackfillworker

conf/init/service/batch/tagbackfillworker/run

@@ -0,0 +1,9 @@
+#! /bin/bash
+
+echo 'Starting tag backfill worker'
+
+QUAYPATH=${QUAYPATH:-"."}
+cd ${QUAYDIR:-"/"}
+PYTHONPATH=$QUAYPATH venv/bin/python -m workers.tagbackfillworker 2>&1
+
+echo 'Repository tag backfill exited'