community: fix ChatEdenAI + EdenAI Tools (#23715)

Fixes for Eden AI Custom tools and ChatEdenAI:
- add missing import in __init__ of chat_models
- add `args_schema` to custom tools. otherwise '__arg1' would sometimes
be passed to the `run` method
- fix IndexError when no human msg is added in ChatEdenAI

libs/community/langchain_community/tools/edenai/image_explicitcontent.py

@@ -1,15 +1,20 @@
 from __future__ import annotations
 
 import logging
-from typing import Optional
+from typing import Optional, Type
 
 from langchain_core.callbacks import CallbackManagerForToolRun
+from langchain_core.pydantic_v1 import BaseModel, Field, HttpUrl
 
 from langchain_community.tools.edenai.edenai_base_tool import EdenaiTool
 
 logger = logging.getLogger(__name__)
 
 
+class ExplicitImageInput(BaseModel):
+    query: HttpUrl = Field(description="url of the image to analyze")
+
+
 class EdenAiExplicitImageTool(EdenaiTool):
     """Tool that queries the Eden AI Explicit image detection.
 
@@ -33,6 +38,7 @@ class EdenAiExplicitImageTool(EdenaiTool):
         pornography, violence, gore content, etc."""
         "Input should be the string url of the image ."
     )
+    args_schema: Type[BaseModel] = ExplicitImageInput
 
     combine_available: bool = True
     feature: str = "image"