Add ActiveCampaign as a new integration for uploading contacts and attach events

[gitfvb]

This should include following functionality

• Load data from ActiveCampaign contacts (incremental/delta if possible)
• Create contacts in ActiveCampaigns, if not existing
• Choose an Event key and create a new Event value
• Optional: Add support for tags to allow better personalisation
• Optional: Add support for filling (and creating) fields for better personalisation
• Load Response Data async, later via webhooks
• Work with fixed lists (maybe a setting in the yaml/json)
• Create an example possible reports
• Optional: Check the duplication of mailing templates, attach a segment (with reference on the Event), fill fields/tags for personalisation and trigger mailing, if this is set in yaml/json

[gitfvb]

Documentation can be found here: https://developers.activecampaign.com/reference/overview

[gitfvb]

Response data can be loaded via v1 of API

or

via Webhooks receiver