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/stop.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+set -e
+
+BASE_DIR=$(cd $(dirname $0) && pwd)
+PIDFILE=element.pid
+CONFIG_BACKUP=config.e2etests_backup.json
+
+cd $BASE_DIR
+
+if [ -f $PIDFILE ]; then
+    echo "Stopping Element server ..."
+    PID=$(cat $PIDFILE)
+    rm $PIDFILE
+    kill $PID
+
+    # revert config file
+    cd element-web/webapp
+    rm config.json
+    if [ -f $CONFIG_BACKUP ]; then
+        mv $CONFIG_BACKUP config.json
+    fi
+fi