[FEATURE] Outgoing Webhooks for TYPO3

A webhook is an automated message sent from one application
to another via HTTP. Most modern web applications have the ability
to communicate either via outgoing or incoming webhooks.
This way of communication allows application users to integrate
multiple systems without writing code (so-called no-code/low-code
integrations).

TYPO3 provides the incoming webhooks part via the system extension
"reactions". This feature now allows configuring
outgoing webhooks in the TYPO3 backend - completing the round trip.

A new backend module is added called "Webhooks" where any
administrative user can create a webhook. At its' core a webhook
consists of a trigger (when something should happen) and a
target URL (what should happen). Every time the webhook is triggered,
an HTTP request is sent to the target URL. With this feature,
the request can be either a POST or a GET request. POST requests
commonly contain data, and GET requests can trigger actions
in third-party systems.

The...