refactor: Split 'Event' docs/types into more specific Event types (#17038)

* Event = Base event type (with preventDefault)
* IpcMainEvent = Event that ipcMain emits (with sender, reply, etc.)
* IpcRendererEvent = Event that ipcRenderer emits (with sender,
senderId, etc.)
* KeyboardEvent = Event that we emit with keyboard flags (ctrlKey,
altKey, etc.)

This will dramatically improve peoples TS experience with IPC events

lib/browser/ipc-main-internal.ts

@@ -5,4 +5,4 @@ const emitter = new EventEmitter()
 // Do not throw exception when channel name is "error".
 emitter.on('error', () => {})
 
-export const ipcMainInternal = emitter
+export const ipcMainInternal = emitter as ElectronInternal.IpcMainInternal