Fix data source search and sync handling

[rossbrg]

Summary

Notion search now returns database-like objects through the data_source filter. This updates the CLI paths that still asked search for database objects, while keeping --property database as a compatibility alias for users.

This also pulls two small shared helpers into place:

• clierrors.Wrap for repeated wrapped CLI errors
• outputFormatExplicit for commands that need to know whether the caller requested structured output

Changes

• Use data_source for search and sync filters.
• Teach sync to cache results returned as data_source objects, including the parent database ID when Notion provides it.
• Keep database/db as accepted search aliases.
• Add tests for search filter behavior and sync cache output.
• Replace repeated local error-wrapping boilerplate in the touched paths.

Testing

• make test
• make build
• make lint