[feature] add TOTP two-factor authentication (2FA) (#3960)

* [feature] add TOTP two-factor authentication (2FA)

* use byteutil.S2B to avoid allocations when comparing + generating password hashes

* don't bother with string conversion  for consts

* use io.ReadFull

* use MustGenerateSecret for backup codes

* rename util functions

web/source/settings/redux/store.ts

@@ -71,7 +71,8 @@ export const store = configureStore({
 					PERSIST,
 					PURGE,
 					REGISTER,
-				]
+				],
+				ignoredPaths: ['api.queries.twoFactorQRCodePng(undefined).data.data'],
 			}
 		}).concat(gtsApi.middleware);
 	}