Add Fastly Snippet support

[TrayserCassa]

Improvement

Add fastly support for the operator to be passed to shopware

Reason

Currently fastly can be configured by shopware but is not configured by the operator.

Information

No response

Definition of Done

• FastlySnippets are created by shopware in fastly

[TrayserCassa]

First we need to create a Token for a service, so that a shop can't use the fastly-api token to configure other services then his own.

[TrayserCassa]

This is required before we merge this:
shopware/docs#1964