Registration/edit updates

[MattIPv4]

Description

Clean up the registration & profile edit forms.

Fixes #668

Test process

Registration form looks correct. Registration form handles category/role checkboxes correctly. Registration form shows errors above the correct inputs.

Edit form looks correct. Edit form handles category/role checkboxes correctly. Edit form shows errors above the correct inputs.

Registration and edit both work correctly in light & dark mode.

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

[MattIPv4]

Will look at that wrapping issue on Monday, not seeing at my default resolution, so I guess I've borked some responsiveness somewhere 👍

[MattIPv4]

All cleaned up, should be good to go