Cleanup csproj files: Remove code duplication for Configuration and entries in Rules project, since it depends on Engine project

[bergmeister]

PR Summary

This is a cleanup of PR #1425:
After that PR, building locally via Visual Studio or dotnet build was not working any more because it did not cater for the Configuration being either Debug or Release. Since the code for Configuration PSV6Debug and PSV6Releasewere the same the condition fore the configuration was removed, thereby removing unnecessary code duplication and making the case ofDebugorReleasework again, whilst not changing existing behaviour. Also: Since theRulesproject depends on theEngine` project, there is no need to duplicate the reference to SMA (which was actually forgotten to be switched from the SDK to SMA in one project).

PR Checklist

• PR has a meaningful title
  • Use the present tense and imperative mood when describing your changes
• Summarized changes
• Change is not breaking
• Make sure all .cs, .ps1 and .psm1 files have the correct copyright header
• Make sure you've added a new test if existing tests do not effectively test the code changed and/or updated documentation
• This PR is ready to merge and is not Work in Progress.
  • If the PR is work in progress, please add the prefix WIP: to the beginning of the title and remove the prefix when the PR is ready.