Add nodeTags and eleTags to VTKHDF recorder HDF5 output

[Copilot]

VTKHDF recorder stored node/element tags only as in-memory structures, making it impossible for external tools (e.g., ParaView) to map sequential indices back to original OpenSees node/element IDs.

Changes

• Constructor: Unconditionally create PointData/nodeTags and CellData/eleTags (1D int, chunked) alongside their corresponding Steps/PointDataOffsets/nodeTags and Steps/CellDataOffsets/eleTags offset tracking datasets.

• writeMesh(): Write theNodeTags and theEleTags once when the mesh is initialized — tags are constant so they are never re-written on domain changes or subsequent steps.

• writeStep(): Append offset 0 to both offset datasets at every time step. Since the data is written once and never changes, all steps point to the beginning of the arrays.

Resulting HDF5 structure

/VTKHDF/
├── PointData/
│   └── nodeTags          # (numNode,) int — original OpenSees node tags
├── CellData/
│   └── eleTags           # (numElement,) int — original OpenSees element tags
└── Steps/
    ├── PointDataOffsets/
    │   └── nodeTags      # always 0 per step (constant data)
    └── CellDataOffsets/
        └── eleTags       # always 0 per step (constant data)