extensions/ipynb/src/deserializers.ts/getNotebookCellMetadata
function getNotebookCellMetadata(cell: nbformat.IBaseCell): CellMetadata {
	// We put this only for VSC to display in diff view.
	// Else we don't use this.
	const propertiesToClone: (keyof CellMetadata)[] = ['metadata', 'attachments'];
	const custom: CellMetadata = {};
	propertiesToClone.forEach((propertyToClone) => {
		if (cell[propertyToClone]) {
			custom[propertyToClone] = JSON.parse(JSON.stringify(cell[propertyToClone]));
		}
	});
	if ('id' in cell && typeof cell.id === 'string') {
		custom.id = cell.id;
	}
	return custom;
}