MOSCOW — The Ukrainian authorities, under pressure to bolster their assertion that once-secret accounting documents show cash payments from a pro-Russian political party earmarked for Donald J. Trump’s campaign chairman, on Thursday released line-item entries, some for millions of dollars.The revelations also point to an outsize role for a former senior member of the pro-Russian political party, the Party of Regions, in directing money to both Republican and Democratic advisers and lobbyists from the United States as the party tried to burnish its image in Washington.
