Update internal `invoke_command()` to retrieve the exit code description from manifest

[SteveL-MSFT]

Summary of the new feature / enhancement

Currently, if the exit code is non-zero, the function returns it as an error. however, the resource manifest can describe what specific exit codes mean. The helper function should be updated so that if the exit code maps to one in the manifest, that information is shown, otherwise it's "unknown".

Proposed technical implementation details (optional)

No response