community: callbacks guard_imports (#21173)

Issue: we have several helper functions to import third-party libraries
like import_uptrain in
[community.callbacks](https://api.python.langchain.com/en/latest/callbacks/langchain_community.callbacks.uptrain_callback.import_uptrain.html#langchain_community.callbacks.uptrain_callback.import_uptrain).
And we have core.utils.utils.guard_import that works exactly for this
purpose.
The import_<package> functions work inconsistently and rather be private
functions.
Change: replaced these functions with the guard_import function.

Related to #21133

libs/community/langchain_community/callbacks/aim_callback.py

@@ -4,19 +4,12 @@ from typing import Any, Dict, List, Optional
 from langchain_core.agents import AgentAction, AgentFinish
 from langchain_core.callbacks import BaseCallbackHandler
 from langchain_core.outputs import LLMResult
+from langchain_core.utils import guard_import
 
 
 def import_aim() -> Any:
     """Import the aim python package and raise an error if it is not installed."""
-    try:
-        import aim
-    except ImportError:
-        raise ImportError(
-            "To use the Aim callback manager you need to have the"
-            " `aim` python package installed."
-            "Please install it with `pip install aim`"
-        )
-    return aim
+    return guard_import("aim")
 
 
 class BaseMetadataCallbackHandler: