refactor(server): event emits

[jrasm91]

• Consolidate the interface for emitting events between services.
• Use event handlers to move logic to appropriate services (decoupling the event source and responses)
• Refactor events: onBootstrap, onShutdown, onConfigUpdate, and onConfigValidate
• In the future, looking to add additional events, like onAssetDelete (before/after)

TODO:

• test cross process events still work correctly (config update, concurrency changes)
• validate start up logic still works correctly and everything is initialized properly

[danieldietzler]

Nice!