User Creation Fixes

What does this MR do and why?

• Fix user creation bug where it would fail when a role was selected.
• Add better feedback on when errors appear on user creation.
• Security improvements for general user creations on roles page.
• Security improvements for general user creations on user page.

Resolves #419 (closed)

How to set up and validate locally

Create a user and assign a role on creation.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• Have you checked this doesn't interfere/conflict/duplicate someone elses work?
• Have you fully tested your changes?
• Have you resolved any lint issues?
• Have you assigned a reviewer?
• Have you applied correct labels?