In BritBox’s “Riot Women,” they’re forming a rock band. In Peacock’s “The ’Burbs” and Netflix’s “How to Get to Heaven From Belfast,” they’re meddling in criminal investigations and uncovering dark secrets. In Netflix’s “The Hunting Wives,” they’re the ones causing crimes and trying to keep them hidden. Meanwhile, the titular heroine of “ Matlock ” on CBS may very well spearhead an operation that brings down Big Pharma.  They say women get ignored as they grow older. But turn on the TV and just