Add amp-analytics support for activecampaign

### Description

The popular email marketing software, [activecampaign](https://www.activecampaign.com/), allows [site tracking via a javascript snippet](https://help.activecampaign.com/hc/en-us/articles/221493708-How-to-set-up-Site-Tracking) added to the page.

It offers typical parameters for event tracking as well.

This is a request to add support for it in amp-analytics.

If this is the wrong place, apologies. I double checked that the [URL in that amp documentation topic](https://amp.dev/documentation/components/amp-analytics/?format=websites#non-integrated-analytics-vendors) does indeed point to the bug report page here from the amp docs.

### Reproduction Steps

Visit activecampaign's [how to setup site tracking](https://help.activecampaign.com/hc/en-us/articles/221493708-How-to-set-up-Site-Tracking) and [overview of site tracking](https://help.activecampaign.com/hc/en-us/articles/221542267-An-overview-of-Site-Tracking) articles to understand their format.

### Relevant Logs

_No response_

### Browser(s) Affected

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### OS(s) Affected

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### Device(s) Affected

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### AMP Version Affected

_No response_