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

typings/internal-helpers.d.ts

@@ -0,0 +1 @@
+declare type Omit<T, K> = Pick<T, Exclude<keyof T, K>>;