Fix: some agent bug (#14829)

### What problem does this PR solve?

fix: 
update null checks to use 'is None' for better clarity
replace RAGFlowSelect with SelectWithSearch in DebugContent
add max height and overflow to DialogContent in ParameterDialog
 remove unused types from DataOperationsForm

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

web/src/pages/agent/debug-content/index.tsx

@@ -1,4 +1,5 @@
 import MarkdownContent from '@/components/next-markdown-content';
+import { SelectWithSearch } from '@/components/originui/select-with-search';
 import { ButtonLoading } from '@/components/ui/button';
 import {
   Form,
@@ -9,7 +10,6 @@ import {
   FormMessage,
 } from '@/components/ui/form';
 import { Input } from '@/components/ui/input';
-import { RAGFlowSelect } from '@/components/ui/select';
 import { Switch } from '@/components/ui/switch';
 import { Textarea } from '@/components/ui/textarea';
 import { IMessage } from '@/interfaces/database/chat';
@@ -147,7 +147,7 @@ const DebugContent = ({
               <FormItem className="flex-1">
                 <FormLabel>{props.label}</FormLabel>
                 <FormControl>
-                  <RAGFlowSelect
+                  <SelectWithSearch
                     allowClear
                     options={
                       q.options?.map((x) => ({
@@ -156,7 +156,7 @@ const DebugContent = ({
                       })) ?? []
                     }
                     {...field}
-                  ></RAGFlowSelect>
+                  ></SelectWithSearch>
                 </FormControl>
                 <FormMessage />
               </FormItem>