BARCELONA, Sept 12 (Reuters) - Former Spanish tennis great Arantxa Sanchez Vicario told a court on Tuesday at the start of a fraud trial that she had trusted her then husband to handle her money and she was not aware of any illegal tampering with her family assets. Sanchez Vicario, 51, and her former husband Josep Santacana stand accused of hiding assets to avoid paying a 7.6 million-euro ($8.14 million) debt to Banque de Luxembourg, including interest, according to the prosecutor. The two,