[FRONTEND] Casuals can’t book

[jji05]

Is your feature request related to a problem? Please describe.

I had noted that casuals can go to -1 game seasons although missed it during review. Need to temporarily fix this so that casuals can book.

Even better would be to properly handle this with different logic.

Describe the solution you'd like

Supposedly we want to maybe remove the frontend limitations of checking user sessions and completely voiding session counts for casuals (booking doesn't affect the casuals booking credit) but instead the backend checks for all bookings made by the casual in the current weeks duration (Monday - Sunday) and determines if the user can book or not based on that.

Additional context

Steps to reproduce:

1. Create a new user on https://staging.uoabadminton.co.nz
2. Try creating a booking by visiting /book (accessible via navbar)
   You're then immediately greeted with the following:

• The expected is ability to book but only 1 session slot available (even for existing bookings). A bonus ([FRONTEND] Revamp book page with sessions user has already booked #962) would be to show what the user has already booked instead of hiding it(marking it as disabled and adding a label or something).

BEFORE MERGING

• Storybooks created where possible
• Tested with react testing library
• Tests written for critical interactions
• PR Reviewed (For non-trivial changes)
• Changes tested after rebasing on master or merging in master (hint: git fetch origin master:master, then git rebase master or git merge master)
• All required PR checks passing

[jji05]

You can consider the entire casuals booking system as a flaw ...