(Reuters) – Gas giant Uniper’s shareholders will on Monday vote on a planned bailout and nationalisation which has so far cost the German government more than 50 billion euros ($53.15 billion). It was hit by long-term Russian partner Gazprom withholding gas exports after Moscow’s invasion of Ukraine. Uniper had to buy gas at higher prices on the spot market to fulfil supply contracts with smaller utilities and industry, forcing Berlin to agree in September to nationalise it. Below is a chronology of the crisis: DECEMBER DEC. 19 – Uniper shareholders vote on the bailout at an extraordinary shar…