By Joanna Plucinska and Andrius Sytas WARSAW/VILNIUS (Reuters) -Russian diplomat Sergiy Andreev was feeling unwelcome on the streets of Warsaw even before protesters doused him with red liquid thrown in his face at short range this week. Soon after Russia’s invasion of Ukraine on Feb. 24, Andreev, who is Moscow’s ambassador in Poland, found the embassy bank accounts had been frozen. Attempts to meet with Polish officials for any level of diplomatic discussion were impossible, he said. His regular barber refused to cut his hair. Insurance companies denied coverage for embassy cars, Andreev said…