Move all event handling to PortalNetwork class

[ScottyPoi]

his PR removes direct EventEmitter inheritance from Network classes and restructurs how events are handled across the Portal Network implementation.
The changes introduce namespaced events and centralize event handling through the PortalNetwork class

Changes

• Remove EventEmitter inheritance from Network classes

• Implement namespaced events using network IDs (e.g., ${networkId}:ContentAdded)

• Move event handling from Network classes to PortalNetwork class

• Update event listeners and emitters across all network implementations

• Update tests

• BaseNetwork classes

  • Removed EventEmitter inheritance
  • Events now emitted through this.portal instead of directly
  • Event names prefixed with network IDs for better isolation

• Event Handling

  • All events are now namespaced with their network ID
  • Removed redundant network ID checks in event handlers