Replace the monolithic HolotapeDefs.xml with categorized holotape definition files and related assets for better organization. Added new HolotapeDefs_* files (Company, Factions, Government, Misc, Personal), created DesignatorDropdown_Holotapes.xml, added About/ModIcon.png, and updated ThingDefs_Holotapes.xml. Removed the old HolotapeDefs.xml and JobDefs_Holotapes.xml. These changes reorganize holotape content and register a designator group and icon for the mod.
