Get returns singleton instance of a Client.

Init initializes Storage Dirs, keyringManager to support access token storage at OS level, also opens a connection to sqlite DB, runs idempotent migrations, starts a goroutine to listen for user login, a goroutine to connect to Ws and listen for recvMsgs to get instance to a client use Get.

ErrApplication code is 0.

LoginState true -> successful login, false -> unauthorized requires login.

WsConnState will be switch cased by tui.TabContainerModel, so making it unique.