LONDON — How do you solve a problem like Rupert Murdoch? That’s the issue now facing sections of his media empire after a damning British parliamentary report labeled the powerful press tycoon unfit to run a major international company. With criticism of Murdoch continuing to mount in the UK, questions were being raised as to what extent the report would harm his business interests both here and in the United States, with some shareholders suggesting it was time to shift power out of Murdoch’s hands.