Renders query result cells as a responsive Bootstrap grid of centred col-md-4 cells, one cell per query value.
LAYOUTGRID — set as ReportType in def_report.
def Render(self, Param1="", Param2="", Param3="") -> str:
Every cell value from every row is wrapped individually in a div.col-md-4.col-centered.text-center. Values are passed through process_text, allowing embedded report tokens in cell content.