[backend] fix: 修复异常处理和类型转换问题

frontend/node_modules/rc-tree-select/assets/index.less

@@ -0,0 +1,2 @@
+@import "./select.less";
+@import "./tree.less";

frontend/node_modules/rc-tree-select/assets/select.less

@@ -0,0 +1,3 @@
+@import '~rc-select/assets/index';
+
+@select-prefix: ~'rc-tree-select';

frontend/node_modules/rc-tree-select/assets/tree.less

@@ -0,0 +1,3 @@
+@import '~rc-tree/assets/index';
+
+@treePrefixCls: ~'rc-tree-select-tree';