Improved vtkCellGrid support in data model and filters

vtkDataObject::GetAttributeTypeAsString

vtkDataObject now provides a new static method GetAttributeTypeAsString(int attributeType) that converts an integer attribute-type constant (e.g., vtkDataObject::POINT, vtkDataObject::CELL) to its string name. This is the symmetric counterpart of the existing GetAssociationTypeAsString.

vtkCellGrid::GetAttributesAsFieldData

vtkCellGrid now overrides GetAttributesAsFieldData(int type) from vtkDataObject. Generic algorithms that call GetAttributesAsFieldData on a vtkDataObject pointer now work correctly when the underlying dataset is a vtkCellGrid.

vtkAttributeDataToTableFilter: Support vtkCellGrid

vtkAttributeDataToTableFilter now accepts vtkCellGrid as input, in addition to the dataset and composite types it already handled. This allows attribute data from a vtkCellGrid to be converted to a table.

vtkCellGridSummaryInformationQuery: New query for per-attribute summary information

A new vtkCellGridSummaryInformationQuery computes per-attribute summary information for a vtkCellGrid in a single traversal. For each vtkCellAttribute, the query accumulates:

• Polynomial order range — the minimum and maximum polynomial order across all cell types that carry the attribute. Retrieve it with GetOrderRange(vtkCellAttribute*).

• Degrees of freedom count — the total number of degrees of freedom for the attribute, correctly accounting for shared DOFs when the attribute uses DOF sharing. Retrieve it with GetNumberOfDOF(vtkCellAttribute*).

The accompanying vtkDGSummaryInformationResponder provides the responder implementation for discontinuous Galerkin ( DG) cell types.