Allow developers to create new "Send to <integration>" rule actions

As a developer, I would like to create a "Send to <my-integration>" rule action.

Today it's possible to create an Application Webhook to subscribe to all events in an account of a given type (this is great for use cases like logging metrics / ETL / etc, but not more nuanced cases where we want only specific events to be sent to our integration webhook).

In order to have our customers send specific events to our integration webhook, we need to guide them to create a rule with a Send to Webhook action, and provide them with a webhook URL. Additionally we need to generate unique URLs for each customer to ensure we can map inbound events to a specific customer.

An ideal solution to this could be allowing developers to create a Rule Action feature in their Application; this would allow Front admin teammates to create rules with specific conditions and a "Send to [Integration]" rule action to send only specific events to our integration webhook.