Taboola: support custom conversions#960

As a user, I need to filter my reports by specific conversions that are listed as custom conversions and for now, this is not possible. It seems that the parameter include_multi_conversions=true needs to be included

https://developers.taboola.com/backstage-api/reference/welcome

Good news, this is available. The Taboola connector exposes a ConversionRules table built with include_multi_conversions=true, so you can report on each custom conversion rule individually. Use Conversion Rule Name (id: conversion_rule_name) to filter to a specific rule and Conversion Rule Conversions (id: conversion_rule_conversions) for its count (id fields conversion_rule_value, conversion_rule_cpa, conversion_rule_roas are also there). These live under the ConversionRules table.