Returns information about a uncle of a block by hash and uncle index position.
Request body sample: {"jsonrpc":"2.0","method":"eth_getUncleByBlockHashAndIndex","params":["0xc6ef2fc5426d6ad6fd9e2a26abeab0aa2411b7ab17f30a99d3cb96aed1d1055b", "0x0"],"id":1}