[algolia-insights] update presets for conversion events

[jkaho]

Summary

Update the available presets / pre-built mappings to make configuring ecommerce conversions less confusing (current presets shown in screenshot).

• Split Send conversion events to Algolia preset into Send purchase events to Algolia and Send add-to-cart events to Algolia. We already treat a generic Conversion Event as a purchase, so this makes it clearer.
• Update Conversion Events action description.
• Mark the Product Added action as deprecated and remove Send product added events to Algolia preset. This maps more closely to our Insights API spec where we consider add-to-carts and purchases "subtypes" of a conversion-type event. The generic conversion event also enables specifying revenue data for multiple objects, which the Product Added event does not.

Testing

This change mainly involved updating the presets. The only change to the actual Destination Actions were in the descriptions, lmk if there's some way I should be testing that.

• Added unit tests for new functionality
• Tested end-to-end using the local server
• [If destination is already live] Tested for backward compatibility of destination. Note: New required fields are a breaking change.
• [Segmenters] Tested in the staging environment
• [Segmenters] [If applicable for this change] Tested for regression with Hadron.

[marinhero]

Hi @jkaho! After approving your PR the CI tests ran and one of them broke for your destination. Mindtaking a look and patching it? Thanks!

[jkaho]

@marinhero thanks for the review 🙏 I've pushed a fix for the failing tests

[marinhero]

Approved and scheduled for deploy on 03/25. Might go out sooner if we run an unscheduled release (we often do). Thank you!

[varadarajan-tw]

@jkaho - This PR has been deployed