Prepare and update closing state

[MattIPv4]

Description

DODX 1735 - Preparing and updating the site and its closing state logic ready for November 1st.

Key changes:

Login button CTA changes to "View your profile" Events page removes references to create an event, rsvp links Registration is closed, replaced with a "see you next year" page

Test process

In the event active state:

• Confirm homepage renders as expected, "Start hacking" CTA
• Confirm you can register correctly
• Confirm you can edit your profile details correctly
• Confirm events page shows create event button & rsvp links

In the event ended state:

• Confirm homepage renders as expected, "View your profile" CTA
• Confirm you cannot register as a new user
• Confirm you can view your profile if already registered
• Confirm you can edit your profile details correctly
• Confirm events page does not show create event button or rsvp links

Requirements to merge

• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my own code
• [ ] I have commented my code in hard-to-understand areas
• [x] My changes generate no new warnings
• [ ] I have added tests that prove my fix is effective or that my feature works
• [x] New and existing unit tests pass locally with my changes