👑 Render different form item in search form

### 🔩 所属模块或组件

ProTable and ProForm

### 🥰 需求描述

It would be great if we could determine in the form item if the item will be rendered as part of a search form or a normal form.

### ⛰ 功能需求适用场景

Sometimes we just need a different component for searching and this additional information would help us a lot.

### 🧐 解决方案

Maybe we could extend `ProFieldFCMode` with value `search`?

### 🚑 其他信息

n/a

Start by reading the ProTable and ProForm components, then trace how ProFieldFCMode is used when rendering form items. Determine how a search-form context should differ from a normal-form context, and confirm that the requested component choice works in both scenarios.

Written by the indexing model from the issue text.