Playwright: Gate server start up with GRAFANA_URL env var (#108302)

* refactor so server is created unless GRAFANA_URL is provided

* update documentation

* don't swallow errors from the server process

e2e-playwright/start-server

@@ -0,0 +1,20 @@
+#!/bin/bash
+
+. scripts/grafana-server/variables
+
+LICENSE_PATH=""
+
+if [ "$1" = "enterprise" ]; then
+    if [ "$2" != "dev" ] && [ "$2" != "debug" ]; then
+      LICENSE_PATH=$2/license.jwt
+    else
+      LICENSE_PATH=$3/license.jwt
+    fi
+fi
+
+if [ "$BASE_URL" != "" ]; then
+    echo -e "BASE_URL set, skipping starting server"
+else
+  ./scripts/grafana-server/start-server $LICENSE_PATH > scripts/grafana-server/server.log
+fi
+