feat: cleaner auth state management

1. removes the "auth-state.update" event since it was bloated and fairly unnecessary
2. adds "creds.update" event that only sends the updated properties of the auth credentials
3. ensure the auth creds are not mutated anywhere, but only with the "creds.update" event
4. Separates the signal credentials from the auth credentials (kinda in progress)
5. in memory key store requires a save function to let one know when to save the keys

!BREAKING_CHANGE

src/Defaults/index.ts

@@ -26,7 +26,7 @@ export const DEFAULT_CONNECTION_CONFIG: SocketConfig = {
     keepAliveIntervalMs: 25_000,
     logger: P().child({ class: 'baileys' }),
 	printQRInTerminal: false,
-    emitOwnEvents: true
+    emitOwnEvents: true,
 }
 
 export const MEDIA_PATH_MAP: { [T in MediaType]: string } = {