The business both Steve Jobs and current CEO of Apple Tim Cook refer to as a “hobby” is the dominant player in the nascent-but-growing “Streaming IP Device” market, according to a new report. Apple TV’s 56 percent share — a figure that represents the more than 13 million units sold through Q1 2013 — is greater than all other competitors in the space combined. While brands like Roku, WD TV, Boxee and Google TV may get more headlines, all but Roku and TiVo have negligible market share in a field that is growing rapidly — as more consumers become “cable cutters” and use alternatives such as Ne…