**Summary**
Issue #16963: When an object is renamed, the morph relation picker still
shows the old name.
**Root cause**
The picker used searchRecord.objectNameSingular from the GraphQL search
response, which can be stale after a rename.
The search record stores the object name at query time, not the current
metadata.
**Solution**
- Updated SingleRecordPickerMenuItem:
- Added useObjectMetadataItems to access current object metadata.
- Look up the current object metadata by morphItem.objectMetadataId.
- Use labelSingular (or nameSingular as fallback) instead of
searchRecord.objectNameSingular for display.
- Updated MultipleRecordPickerMenuItemContent:
- Use objectMetadataItem.labelSingular (already available as a prop)
instead of searchRecord.objectNameSingular.
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Co-authored-by: Marie Stoppa <marie.stoppa@essec.edu>
