refactor(stock): 重构组件的过滤参数处理逻辑

- 将单一的 filterParams 对象拆分为多个键值对，分别存储操作符和值
- 优化了过滤参数的处理方式，提高了代码可读性和可维护性

src/main/webapp/app/entities/stock/stock.component.ts

@@ -73,7 +73,8 @@ export default defineComponent({
         const processedParams = showFilter.value
           ? Object.entries(filterParams.value).reduce((acc, [key, filterParam]) => {
               if (filterParam.value !== null && filterParam.value !== '') {
-                acc[key] = encodeURIComponent(JSON.stringify({ op: filterParam.op, value: filterParam.value }));
+                acc[`${key}[op]`] = filterParam.op;
+                acc[`${key}[value]`] = filterParam.value;
               }
               return acc;
             }, {})