fix: update sql code & download prettily JSON

frontend/src/views/OlapConstructor.vue

@@ -1062,6 +1062,7 @@ async function saveQuery() {
     if (!res.ok) throw new Error(await res.text())
     showNotification('OlapConstructor.notifications.saveSuccess', 'success')
     isDirty.value = false
+    await fetchSql()
   } catch (e: any) {
     showNotification('OlapConstructor.notifications.saveError', 'error',  { error: e.message })
   }

src/main/java/su/xserver/iikocon/MainVerticle.java

@@ -649,7 +649,7 @@ public class MainVerticle extends AbstractVerticle {
       rc.response()
         .putHeader("Content-Type", "application/json")
         .putHeader("Content-Disposition", "attachment; filename=olap_export.json")
-        .end(fullJson.encode());
+        .end(fullJson.encodePrettily());
     });
 
     return router;