feat: users table

[kayra1]

Description

This change adds the user table and the accompanying aside form to add a new user to GoCert. The tab is only visible to an Admin user, and a regular user will only see the certificate requests table.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have made corresponding changes to the documentation
• I have added tests that validate the behaviour of the software
• I validated that new and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[DanielArndt]

This is the first typescript I've looked at in years, so take my approval with a grain of salt...