EHN: add "show" option to map config

src/core/js/ext_map.js

@@ -881,6 +881,7 @@ var caosdb_map = new function () {
 
         this.show_map = function () {
             logger.trace("enter show_map");
+            sessionStorage["caosdb_map.show"] = "true";
             $(".caosdb-f-map-panel").show(900, () => this
                 ._toggle_cb());
         }