Add analytics to the portal

[gndelia]

Description

This PR adds Umami to track analytics. umami-analytics-next was published as part of this PR.

NEXT_PUBLIC_ANALYTICS_URL and NEXT_PUBLIC_ANALYTICS_WEBSITE_ID were set on Github (they are only enabled for prod)

Screenshots

No visible changes to the user

Related issue(s)

Closes #447

Checklist

• [x] Manual testing passed.
• [ ] Automated tests added, or N/A.
• [ ] Documentation updated, or N/A.
• [x] Environment variables set in CI, or N/A.

[gndelia]

I forgot, I need to allow the script to load (considering security headers, as the script is on an external domain )

[gndelia]

Added 7b721ba in which the domain where the analytics script lives is added to the security headers