Template for metadata fields across multiple NWB files (e.g., allowing users to reuse the same subject/session metadata during ingest through NWB Guide or Neurosift)

Enable users to define and apply reusable metadata templates for common fields (e.g., subject or session information) across multiple NWB files. This would streamline data entry during ingest workflows in tools like NWB Guide or Neurosift and help ensure consistency.