Feature Request: Preserve OGR source layer name as a feature tag in case of classify to ISSprOM or ISOM by funkcion "find"

**Is your feature request related to a problem? Please describe.** When importing generic geospatial data via OGR gpkg many features may not match the symbol set immediately and are imported with a fallback symbol (or no symbol). Currently, the user loses the information about which source layer the feature came from. This makes manual classification after import very difficult, as the user cannot distinguish between different source types (e.g., "building" vs. "paved area") if they end up with the same default geometry. **Describe the solution you'd like** I propose adding the original OGR layer name as a string tag to the imported features. This would allow users to identify the source of the object in the tags editor and assign the correct symbol manually. **Describe alternatives you've considered** The tag could be named something like `source_layer` or `_ogr_layer`. **Additional context** I have been working with Czech Cadastral data (gpkg) where layer names contain crucial information for symbol mapping. Possible implementation in `OgrFileImport::importLayer`: ```cpp // Example logic const char* layer_name = OGR_L_GetName(layer); if (layer_name) { // Add tag to the Mapper feature // key: "source_layer", value: layer_name }