[Realtime] No access token on startup if signed in, until the next token refresh

[MilesV64]

It seems that SupabaseClient gives the access token to Realtime in handleTokenChanged. However, if the event is intialSession, it passes a nil access token even if there is a valid one saved in keychain storage. It would be good if it passes the stored access token on initial session if there is a valid one.