Many of central Indiana’s banks are filling their own safe-deposit boxes, but they’re not stuffing them with jewelry, legal documents or blackmail material. They’re banking parcels of land. The sites often are in fast-growing suburbs or redevelopment areas that hold potential for new brickand-mortar bank branches, sometimes several years down the road. Competition can be fierce for the prime sites, and other financial institutions aren’t the only nemesis for banks: Walgreens and CVS also are fighting over the best ground,…