I2I: amp-analytics support for Taboola

## Summary
Tracking a page view on publisher pages with Taboola integrated on them

## Design document

## Motivation

A clear and concise description of any alternative solutions or features you've considered.

## Additional context

## Launch tracker

cc @ampproject/wg-analytics

The issue identifies amp-analytics and Taboola but names no file, test, entry point, or design document. Begin by defining the intended page-view tracking behavior for publisher pages with Taboola, then document and validate the integration; done means those page views are tracked as agreed.

Written by the indexing model from the issue text.