LuaEntityEnricher

Installed on plugin enable to contribute FMM-specific fields (is_modeled, is_prop, and the nested model sub-table) to every Lua entity table built by the shaded Magmacore scripting layer. Also forwards to EliteMobsEntityEnricher when EliteMobs is present, so scripts running inside FMM see elite/boss flags without Magmacore having to reflectively bridge the two plugins.