Change some events, fix p2 sending gameend twice

- Fixed gameend being sent twice in p2
- Add `ready`, `loader-error`, and `song-select-random` events
- Fixed `session-start` not firing when invited, added event detail
- Fixed `language-change` being fired at startup
- Fixed `version-link` and `about-link` firing twice
- "#song=" will fire `song-select-difficulty`
- Removed `key-events` and `scoresheet-player2`, merged with `scoresheet` and made it more detailed

public/src/js/keyboard.js

@@ -259,11 +259,5 @@ class Keyboard{
 		if(this.controller.multiplayer === 1){
 			pageEvents.remove(window, "beforeunload")
 		}
-		if(this.controller.multiplayer !== 2){
-			pageEvents.send("key-events", {
-				keyboard: this.keyboardEvents,
-				gamepad: this.gamepad.gamepadEvents
-			})
-		}
 	}
 }