As if the downtown dining scene were not sufficiently awash in steakhouses, Dine/amic Hospitality Group — the team behind Public House and Siena Tavern — has entered the fray with the glamorously appointed Prime & Provisions, 222 N. LaSalle St.Art nouveau-inspired wrought iron frames a dining room full of sumptuous fabrics, capped by a warmly glowing vaulted glass ceiling. The background music, it should be noted, narrowly skirts the threshold of impeding conversation without crossing it.Unlike many new …