Track link clicks in `amp-story-auto-analytics`

### Description

With regular `amp-analytics` is was possible to add events for triggers like `story-page-attachment-enter` and `story-click-through` to track clicks on inline links and page attachments / outlinks.

This capability is currently missing from `amp-story-auto-analytics` and I think would be useful to add tracking for these & potentially also surface that in the Data Studio dashboard for example.

### Alternatives Considered

Add a custom `amp-analytics` configuration in addition to `amp-story-auto-analytics` that tracks these events.

### Additional Context

_No response_

Start by locating the amp-story-auto-analytics entry point and comparing its behavior with regular amp-analytics. Review how the story-page-attachment-enter and story-click-through events are handled for inline links, page attachments, and outlinks. Done means these clicks are tracked by amp-story-auto-analytics; assess separately whether the Data Studio dashboard should surface them.

Written by the indexing model from the issue text.