Feat: Translate the system prompt of the generate operator #3993 (#4283)

### What problem does this PR solve?

 Feat: Translate the system prompt of the generate operator #3993

### Type of change


- [x] New Feature (non-breaking change which adds functionality)

web/src/pages/flow/form/generate-form/index.tsx

@@ -25,7 +25,7 @@ const GenerateForm = ({ onValuesChange, form, node }: IOperatorForm) => {
       </Form.Item>
       <Form.Item
         name={['prompt']}
-        label="System"
+        label={t('systemPrompt')}
         initialValue={t('promptText')}
         tooltip={t('promptTip', { keyPrefix: 'knowledgeConfiguration' })}
         rules={[