Add Privacy Friendly analytics

[Flajt]

Is your feature request related to a problem? Please describe. As a developer I want to know how many users are using the project, where are they from and how many signature, verifications etc. are happening. As privacy friendly as possible!

Describe the solution you'd like Using a privacy friendly analytics service with a nice free tier. Something like telemetrydeck.com

Describe alternatives you've considered

• Implementing a custom analytics service with focus on mobile devices and privacy (TODO)

Additional context I don't care for each user journey, I just want a general overview about whats up, no need for ID linking or email address attachement and stuff.

Using telemetrydeck would require a port to flutter bc they currently offer only android and ios sdks. Should be a good learning experience.

[Flajt]

Website has, for mobile I'm waiting for telemetrydeck response

[Flajt]

Official telemetrydeck lib for flutter has been released. Consider implementing it.