docs, templates: update schema imports to core (#17885)

- chat models, messages
- documents
- agentaction/finish
- baseretriever,document
- stroutputparser
- more messages
- basemessage
- format_document
- baseoutputparser

---------

Co-authored-by: Bagatur <baskaryan@gmail.com>

libs/experimental/langchain_experimental/sql/vector_sql.py

@@ -1,4 +1,5 @@
 """Vector SQL Database Chain Retriever"""
+
 from __future__ import annotations
 
 from typing import Any, Dict, List, Optional, Sequence, Union
@@ -7,11 +8,12 @@ from langchain.callbacks.manager import CallbackManagerForChainRun
 from langchain.chains.llm import LLMChain
 from langchain.chains.sql_database.prompt import PROMPT, SQL_PROMPTS
 from langchain.prompts.prompt import PromptTemplate
-from langchain.schema import BaseOutputParser, BasePromptTemplate
 from langchain_community.tools.sql_database.prompt import QUERY_CHECKER
 from langchain_community.utilities.sql_database import SQLDatabase
 from langchain_core.embeddings import Embeddings
 from langchain_core.language_models import BaseLanguageModel
+from langchain_core.output_parsers import BaseOutputParser
+from langchain_core.prompts import BasePromptTemplate
 
 from langchain_experimental.sql.base import INTERMEDIATE_STEPS_KEY, SQLDatabaseChain