Pageviews metadata

[Blaumaus]

Tracking script: Let's add support for metadata parameters like:

trackPageview('/blog/why-google-analytics-sucks', {
  meta: {
    author: 'Andrii',
    storyType: 'opinion'
  }
})

For the trackViews function, metadata can be attached within the callback method.

Dashboard: I think the best approach is to add a new Custom events panel tab called "Pageview properties". It will contain a list of properties that exist (like "author" or "storyType").

If user clicks on "author", they will see a list of values, how many pages exist with these values and % like "Andrii", "Tom", "John", etc.

Users should also be able to add these metavalues as filers.

API: I suppose the approach to store metadata for pageviews should not be different from how we store custom events metadata.

[Blaumaus]

API: https://github.com/Swetrix/swetrix-api/pull/239 FE: https://github.com/Swetrix/swetrix-fe/pull/431 Tracking script: https://github.com/Swetrix/swetrix-js/pull/13 Docs: https://github.com/Swetrix/docs/pull/23