Refractor AttendeeFragment (multiple problems)

[anhanh11001]

Describe the bug

• Many problems regarding screen rotation
  Attendee list, ticket information disappear, options to pick the payment options
• Many unnecessary variables are kept inside the View (fragment) -> can be deleted or should be moved to ViewModel
• Redundant methods on both fragment file and view-holder file.
• The free events are not bookable

Additional context
Related issue: #1728 #1004 #967

Would you like to work on the issue?
Yes