fix: return also v1 error from generated code

[vlastahajek]

Proposed Changes

Generated server stubs return also an error message from InfluxDB 1.x forward compatible API.

Checklist

• [X] CHANGELOG.md updated
• [X] Rebased/mergeable
• [X] A test has been added if appropriate
• [X] Tests pass
• [X] Commit messages are in semantic format