Update Consent UX and Privacy Policy for the Matomo use-case

Description

Right now the Clean Insights backend does logs part of IP addresses if metrics are sent by the Matomo Javascript library.

With the Clean Insights Javascript library, no IPs are logged.

Details discussed at #87 (closed).

Tasks

• Update the Privacy Policy and the Consent UX to reflect what is happening ref. IP logging.

Time estimation

• Complexity: very small (0.5 day)
• Uncertainty: low (x1.1)
• Reference (adapted)