Remove unnecessary syntax.
Correct/fix navigate.js redirect behaviour.

- Do complete page reload only on protocols switch.
- Improve anchor conservation.
- Drop isSameOriginUrl function.
Drop `env.extras.isUserIdChanged`.
Drop "logged_in" cookie hook.
Increase cookies serialization priority value.
Drop 'secure' flag from session id cookie.

It should be set by another hook.
Drop orphaned `isEncryptionAllowed` utility function.
Move `findBindConfig` utility to `env.js` file.
Rename `findBindConfig` to `findServerSocketConfig`.
Rename `prefixOptions` variable to `linkDefaults`.
Reply with "Bad Request" if "Host" header is missed.