Joe Otterson TV ReporterThe upcoming Fox country music drama “Monarch” has cast its final two series regulars.Martha Higareda and Emma Milani have both joined the series alongside previously announced cast members Beth Ditto, Trace Adkins, Susan Sarandon, Anna Friel, Joshua Sasse, Meagan Holder, and Inigo Pascual.The series follows America’s “first family” of country music, including mother Dottie Cantrell Roman (Sarandon), father Albie Roman (Adkins) and daughters Gigi Taylor-Roman (Ditto) and