Add error handling of invalid CQP queries

app/templates/corpora/analyse_corpus.html.j2

@@ -258,7 +258,17 @@
         });
       }
       return;
-    }
+    } else if (message === "CQI_CQP_ERROR_GENERAL") {
+        queryResultsTableElement.classList.add("hide");
+        let toast = M.toast({"classes": "red", "html": `<span>Invalid query entered!</span><button class="btn-flat toast-action white-text" data-action="close"><i class="material-icons">close</i></button>`});
+        let toastActionElement = toast.el.querySelector(".toast-action[data-action='close']");
+        if (toastActionElement) {
+          toastActionElement.addEventListener("click", function() {
+            toast.dismiss();
+          });
+        }
+        return;
+      }
 
     var matchElement;
     var matchTextTitlesElement;