The European Union signaled on Friday that it was poised to unlock billions of euros in frozen funds for Hungary, a major step toward the thawing of relations with Budapest after the election defeat last month of Viktor Orban, then the prime minister. Brussels would release 16.4 billion euros (about $19.1 billion) out of more than €19 billion it had withheld to push Mr. Orban’s government into accepting anti-corruption and rule of law policies. His yearslong refusal was at the heart of a re-