Refs #20970; Changed the following:

- Got rid of eea.icons and eea.cache packages dependencies since the messages
  styles are already set by other packages and eea.cache was used
  for the controlpanel
- Removed the control panel entry; it's just as easy to customize
  eea.messages.init.js if there are other settings needed
  and by removing the control panel settings we make the plugin faster
  since we don't do a browser request to get the json file
- Cleaned package of leftover traces from eea.package package generation
  which we no longer use