fix(callback): add error handling for callback service

[Phil91]

Description

add error handling to the callback service

Why

Currently the callback is send without a check if the call was successful, this results in the process step always succeeding even if the callback call failed.

Issue

Refs: #67

Checklist

• I have performed a self-review of my own code
• I have successfully tested my changes locally
• I have added tests that prove my changes work
• I have checked that new and existing tests pass locally with my changes
• I have commented my code, particularly in hard-to-understand areas
• I have added copyright and license headers, footers (for .md files) or files (for images)