[Feature] Add document retrieval QA (#5020)

* add langchain

* add langchain

* Add files via upload

* add langchain

* fix style

* fix style: remove extra space

* add pytest; modified retriever

* add pytest; modified retriever

* add tests to build_on_pr.yml

* fix build_on_pr.yml

* fix build on pr; fix environ vars

* seperate unit tests for colossalqa from build from pr

* fix container setting; fix environ vars

* commented dev code

* add incremental update

* remove stale code

* fix style

* change to sha3 224

* fix retriever; fix style; add unit test for document loader

* fix ci workflow config

* fix ci workflow config

* add set cuda visible device script in ci

* fix doc string

* fix style; update readme; refactored

* add force log info

* change build on pr, ignore colossalqa

* fix docstring, captitalize all initial letters

* fix indexing; fix text-splitter

* remove debug code, update reference

* reset previous commit

* update LICENSE update README add key-value mode, fix bugs

* add files back

* revert force push

* remove junk file

* add test files

* fix retriever bug, add intent classification

* change conversation chain design

* rewrite prompt and conversation chain

* add ui v1

* ui v1

* fix atavar

* add header

* Refactor the RAG Code and support Pangu

* Refactor the ColossalQA chain to Object-Oriented Programming and the UI demo.

* resolved conversation. tested scripts under examples. web demo still buggy

* fix ci tests

* Some modifications to add ChatGPT api

* modify llm.py and remove unnecessary files

* Delete applications/ColossalQA/examples/ui/test_frontend_input.json

* Remove OpenAI api key

* add colossalqa

* move files

* move files

* move files

* move files

* fix style

* Add Readme and fix some bugs.

* Add something to readme and modify some code

* modify a directory name for clarity

* remove redundant directory

* Correct a type in  llm.py

* fix AI prefix

* fix test_memory.py

* fix conversation

* fix some erros and typos

* Fix a missing import in RAG_ChatBot.py

* add colossalcloud LLM wrapper, correct issues in code review

---------

Co-authored-by: YeAnbang <anbangy2@outlook.com>
Co-authored-by: Orion-Zheng <zheng_zian@u.nus.edu>
Co-authored-by: Zian(Andy) Zheng <62330719+Orion-Zheng@users.noreply.github.com>
Co-authored-by: Orion-Zheng <zhengzian@u.nus.edu>

applications/ColossalQA/tests/test_document_loader.py

@@ -0,0 +1,21 @@
+import os
+from colossalqa.data_loader.document_loader import DocumentLoader
+
+
+def test_add_document():
+    PATH = os.environ.get('TEST_DOCUMENT_LOADER_DATA_PATH')
+    files = [[PATH, 'all data']]
+    document_loader = DocumentLoader(files)
+    documents = document_loader.all_data
+    all_files = []
+    for doc in documents:
+        assert isinstance(doc.page_content, str)==True
+        if doc.metadata['source'] not in all_files:
+            all_files.append(doc.metadata['source'])
+    print(all_files)
+    assert len(all_files) == 6
+
+
+if __name__=='__main__':
+    test_add_document()
+