fix dropdownlist api

Author: Thomasr

server/api-service/lowcoder-server/src/main/java/org/lowcoder/api/query/LibraryQueryController.java

@@ -35,13 +35,13 @@ public class LibraryQueryController implements LibraryQueryEndpoints
     private GidService gidService;
 
     @Override
-    public Mono<ResponseView<List<LibraryQueryAggregateView>>> dropDownList(@RequestParam(required = false) String name) {
+    public Mono<ResponseView<List<LibraryQueryAggregateView>>> dropDownList(@RequestParam(required = false, defaultValue = "") String name) {
         return libraryQueryApiService.dropDownList(name)
                 .map(ResponseView::success);
     }
 
     @Override
-    public Mono<ResponseView<List<LibraryQueryView>>> list(@RequestParam(required = false) String name) {
+    public Mono<ResponseView<List<LibraryQueryView>>> list(@RequestParam(required = false, defaultValue = "") String name) {
         return libraryQueryApiService.listLibraryQueries(name)
                 .map(ResponseView::success);
     }

server/api-service/lowcoder-server/src/main/java/org/lowcoder/api/query/LibraryQueryEndpoints.java

@@ -29,7 +29,7 @@ public interface LibraryQueryEndpoints
 		    description = "Retrieve Library Queries in a dropdown format within Lowcoder, suitable for selection in user interfaces."
 	)
     @GetMapping("/dropDownList")
-    public Mono<ResponseView<List<LibraryQueryAggregateView>>> dropDownList(@RequestParam(required = false) String name);
+    public Mono<ResponseView<List<LibraryQueryAggregateView>>> dropDownList(@RequestParam(required = false, defaultValue = "") String name);
 
 	@Operation(
 			tags = TAG_LIBRARY_QUERY_MANAGEMENT,
@@ -38,7 +38,7 @@ public interface LibraryQueryEndpoints
 		    description = "Retrieve a list of Library Queries for a specific Organization within Lowcoder."
 	)
     @GetMapping("/listByOrg")
-    public Mono<ResponseView<List<LibraryQueryView>>> list(@RequestParam(required = false) String name);
+    public Mono<ResponseView<List<LibraryQueryView>>> list(@RequestParam(required = false, defaultValue = "") String name);
 
 	@Operation(
 			tags = TAG_LIBRARY_QUERY_MANAGEMENT,