Update the Registry UI tech stack

[EricWittmann]

The following updates need to be made:

• Migrate to vite
• Upgrade Patternfly to v5
• Separate UI from back-end [?]
• Format using Apicurio eslint format
• Simplify auth layer (remove keycloak.js support)
• Use generated REST API client [?]

[EricWittmann]

All of these except for the final bullet point are done!