By Herbert Lash (Reuters) -The dollar rose to fresh 20-year highs on Wednesday and the euro tumbled to a new two-decade low as rising energy prices and potential shortages cast a long shadow over the euro zone’s economy. The dollar index, which tracks the greenback versus a basket of six currencies, shot above 107, while the euro tumbled below $1.02, both for the first time since December 2002. The dollar has strengthened as energy prices are high and the Federal Reserve has been raising interest rates more quickly than most other central banks, said Shahab Jalinoos, global head of macro tradi…