* Add LoginPluginMessageBox to allow sending custom login plugin messages
* throw in ConnectionManager because AsyncUtils has a try catch
* Stack requests in AsyncPlayerPreLoginEvent so the user-facing API is scoped to the login stage
* Fix addPluginRequest javadoc
* feat: encapsulate velocityproxy logic, other minor tweaks
* fix: revert velocityproxy changes
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Co-authored-by: mworzala <mattheworzala@gmail.com>