Add external plugin (issue in wrong repo lol) for reporting build errors

[ChillerDragon]

Add a plugin hook to update.sh that collects the latest build errors and posts them to discord:

• Specific webhook url as plugin config but also add a generic non plugin specific fallback webhook url in DDNetPP/server
  As a user i do not want to configure the same webhook url for 10 plugins 10 times

Also add an option to post them in game with fifo or econ:

• as motd for all joining players
• or as echo in rcon if a new admin logs in