Fix class promotion

[leo-gan]

In LangChain, all module classes are enumerated in the __init__.py file of the correspondent module. But some classes were missed and were not included in the module __init__.py

This PR:

• added the missed classes to the module __init__.py files
• __init__.py:__all_ variable value (a list of the class names) was sorted
• langchain.tools.sql_database.tool.QueryCheckerTool was renamed into the QuerySQLCheckerTool because it conflicted with langchain.tools.spark_sql.tool.QueryCheckerTool
• changes to pyproject.toml:
  • added pgvector to pyproject.toml:extended_testing
  • added pandas to pyproject.toml:[tool.poetry.group.test.dependencies]
  • commented out the streamlit from collbacks/__init__.py, It is because now the streamlit requires Python >=3.7, !=3.9.7
• fixed duplicate names in tools
• fixed correspondent ut-s

Who can review?

@hwchase17
@dev2049

[vercel]

@leo-gan is attempting to deploy a commit to the LangChain Team on Vercel.

A member of the Team first needs to authorize it.

[hwchase17]

thanks!