feat(cost): 修改生产成本明细新增接口返回新增记录的ID

将CostProdDetailController的add方法返回值从R<Void>改为R<Long>，并返回新增记录的detailId。同时将ICostProdDetailService和CostProdDetailServiceImpl的insertByBo方法返回值从Boolean改为Long，直接返回新增记录的ID，便于前端获取新增数据标识。

klp-cost/src/main/java/com/klp/cost/controller/CostProdDetailController.java

@@ -71,8 +71,8 @@ public class CostProdDetailController extends BaseController {
     @Log(title = "生产成本明细", businessType = BusinessType.INSERT)
     @RepeatSubmit()
     @PostMapping()
-    public R<Void> add(@Validated(AddGroup.class) @RequestBody CostProdDetailBo bo) {
-        return toAjax(iCostProdDetailService.insertByBo(bo));
+    public R<Long> add(@Validated(AddGroup.class) @RequestBody CostProdDetailBo bo) {
+        return R.ok(iCostProdDetailService.insertByBo(bo));
     }
 
     /**