[Bug] External storage won't run on user payloads in signal with start

[tconley1428]

What are you really trying to do?

Have a user payload provided to signal with start and be externally stored.

Describe the bug

External storage uses a separate visitor which is not system nexus aware.

Minimal Reproduction

Environment/Versions

• OS and processor: [e.g. M1 Mac, x86 Windows, Linux]
• Temporal Version: [e.g. 1.14.0?] and/or SDK version
• Are you using Docker or Kubernetes or building Temporal from source?

Additional context