Fix redirect behavior from reservations to registrations for new users, show existing reservation on /reservations page for logged in user

[brcsrc]

Summary

fixes the redirect behavior if a not logged in / non existent user tries to make a reservation. it should now take them to login or registration during the registration process and then take them back to the same room summary so they can continue the user flow

theres a bug with the right room being selected between page transitions

Testing

1. went to http://ec2-34-216-220-197.us-west-2.compute.amazonaws.com:8080/reservation/ and made a reservation without being logged in and got redirected correctly
2. after reservation was complete, went back to http://ec2-34-216-220-197.us-west-2.compute.amazonaws.com:8080/reservation/ to see the reservation summary

Issues

playing catch up for reservation summary task from mod 8

[brcsrc]

lgtm 👍