I know of lipu Linku. However, it doesn’t have the names for all the ma and toki (e.g. toki Inli, ma Mewika, etc.), and I do not know all the endonyms so that I can tokiponize as needed. Is there a site with those? I know Wiktionary has some, but only in an appendix and it’s inconvenient to access.
I don’t think there will be a standardized list of all the place names. mi pilin e ni: jan mute li kama sona e toki pona la nasin jan en nasin kalama li ken ante.
What may be interesting to see is how each country’s speaker would tokiponize their own stuff. I know jan Sonja called my country ma Malasija in lipu pu, but I would naturally sound more as ma Malesija, and I know that jan poka mi li pilin sama.