DES MOINES — Iowa’s foray into sports betting initially was viewed as a minor addition to casinos’ main gambling menu, but for a time in a coronavirus-ravaged wagering landscape it became the only game in town.Financial reports issued by the state Racing & Gaming Commission show Iowans wagered about $368 million in fiscal 2020 on the outcome of professional and collegiate sports competition — more than $223.6 million done online — even though much of the activity was shut down starting in March due to the COVID-19 outbreak.The new betting option that began last Aug.