Add hamburger icon to tab bar to help users find drawer

It isn't clear that the drawer menu exists, we have gotten multiple reports with users confused because they didn't get to the drawer menu. We should add a "hamburger" icon to the tab menu, to signal the existence of the drawer.

Original issue title: No obvious way to sign out account after it was deleted
Original issue text: I deleted my account over on pixelfed.social and after doing that I had to use the Android settings to erase data to be able to use the app with another account