Show scm messages in errors

[pfeuffer]

Proposed changes

This change will include messages from the scm protocol in modification or merge errors, so that information from pre receive hooks aren't lost in transmission but can be displayed.

Your checklist for this pull request

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• PR is well described
• Related issues linked to PR if existing and labels set
• Target branch is not master (in most cases develop should bet the target of choice)
• Code does not conflict with target branch
• New code is covered with unit tests
• CHANGELOG.md updated
• Definition of Done's fulfilled: DoD // UI DoD
• Documentation updated (only necessary for new features or changed behaviour)

Checklist for branch merge request (not required for forks)

• Branch is green/blue on Jenkins
• Quality Gate passed on SonarQube

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!

0 Bugs
0 Vulnerabilities (and 0 Security Hotspots to review)
0 Code Smells

48.3% Coverage
0.0% Duplication