cli_demo.py、api.py: 兼容loader加载器

loader.py: 模型重载
定义 generatorAnswer 增加 AnswerResultStream
   定义generate_with_callback收集器，在每次响应时将队列数据同步到AnswerResult
requirements.txt 变更项目依赖

bug fixed & ui Moidfy

2: add backgound image

* 1: 基于langchain的bing search agent添加bing搜索支持(百度不靠谱,Google不可用)
2: 调整输入框交互模式,对话/知识库/搜索,三选一

* fixed bug of message have no text

---------

Co-authored-by: root <jv.liu@i1368.com>

add Knowledge Base delete and file delete

* 添加加命令行工具

* 添加加命令行工具

---------

Co-authored-by: zqt <1178747941@qq.com>
Co-authored-by: imClumsyPanda <littlepanda0716@gmail.com>

更改目前流式对话的传入模式，使其可以支持多轮对话，体现在新增参数：history、knowledge_base_id

fixed bug of upload file use fixed url