The Ministry of Folk presents an evening of Irish session tunes live from Medford with Matt and Shannon Heaton. The couple have been huge figures in the Boston Irish scene for decades, playing  updated and traditional Irish music on flute, accordion, guitar, bouzouki, and voices. Matt has performed with countless ensembles, including the Karan Casey Band, Boys of the Lough, and Robbie O’Connell. Shannon co-founded Boston’s Celtic Music Fest and served on its board for 15 years, creating performance and…