Mono repo -> Master (#22553)

Combines the following repositories into one:

https://github.com/mattermost/mattermost-server
https://github.com/mattermost/mattermost-webapp
https://github.com/mattermost/focalboard
https://github.com/mattermost/mattermost-plugin-playbooks

server/scripts/wait-for-system-start.sh

@@ -0,0 +1,20 @@
+#!/bin/bash
+
+total=0
+max_wait_seconds=60
+
+echo "waiting $max_wait_seconds seconds for the server to start"
+
+while [[ "$total" -le "$max_wait_seconds" ]]; do
+    if bin/mmctl system status --local 2> /dev/null; then
+        exit 0
+    else
+        ((total=total+1))
+        printf "."
+        sleep 1
+    fi
+done
+
+printf "\nserver didn't start in $max_wait_seconds seconds\n"
+
+exit 1