Rebrand various CI scripts and modules

This replaces Riot with Element in various CI scripts, modules, parameters, etc.
This _should_ be the last major rebranding pass (hopefully).

Fixes https://github.com/vector-im/element-web/issues/14894

test/end-to-end-tests/element/start.sh

@@ -0,0 +1,54 @@
+#!/usr/bin/env bash
+set -e
+
+PORT=5000
+BASE_DIR=$(cd $(dirname $0) && pwd)
+PIDFILE=$BASE_DIR/element.pid
+CONFIG_BACKUP=config.e2etests_backup.json
+
+if [ -f $PIDFILE ]; then
+    exit
+fi
+
+cd $BASE_DIR/
+echo -n "Starting Element on http://localhost:$PORT ... "
+pushd element-web/webapp/ > /dev/null
+
+# backup config file before we copy template
+if [ -f config.json ]; then
+    mv config.json $CONFIG_BACKUP
+fi
+cp $BASE_DIR/config-template/config.json .
+
+LOGFILE=$(mktemp)
+# run web server in the background, showing output on error
+(
+    source $BASE_DIR/env/bin/activate
+    python -m ComplexHTTPServer $PORT > $LOGFILE 2>&1 &
+    PID=$!
+    echo $PID > $PIDFILE
+    # wait so subshell does not exit
+    # otherwise sleep below would not work
+    wait $PID; RESULT=$?
+
+    # NOT expected SIGTERM (128 + 15)
+    # from stop.sh?
+    if [ $RESULT -ne 143 ]; then
+        echo "Failed"
+        cat $LOGFILE
+        rm $PIDFILE 2> /dev/null
+    fi
+    rm $LOGFILE
+    exit $RESULT
+)&
+# to be able to return the exit code for immediate errors (like address already in use)
+# we wait for a short amount of time in the background and exit when the first
+# child process exits
+sleep 0.5 &
+# wait the first child process to exit (python or sleep)
+wait -n; RESULT=$?
+# return exit code of first child to exit
+if [ $RESULT -eq 0 ]; then
+    echo "Running"
+fi
+exit $RESULT