Add export of specific mesh objects to file

### 📝 Description of the feature

Option to export list of cell zonelets or face zonelets to file

### 💡 Steps for implementing the feature

_No response_

### 🔗 Useful links and references

_No response_

The issue identifies no implementation files, tests, entry points, or references. Start by locating the existing mesh export functionality and the representations of cell zonelets and face zonelets; clarify the target file format and API before implementation. Done means a caller can select specific zonelets and export them to a file with coverage for the chosen behavior.

Written by the indexing model from the issue text.