feat: Add progress bar for async LLM generation (#522)

* feat: Add progress bar for async LLM generation

- Add tqdm_asyncio.gather() to show real-time progress during LLM calls
- Minimal change: 1 import + 1 line modification
- Shows block name, completed/total requests, elapsed time, and rate

* style: Fix import sorting for ruff linter

Author: ashtarkb

src/sdg_hub/core/blocks/llm/llm_chat_block.py

@@ -7,6 +7,7 @@
 
 from litellm import acompletion, completion
 from pydantic import ConfigDict, Field, SecretStr, field_validator
+from tqdm.asyncio import tqdm_asyncio
 import litellm
 
 # Third Party
@@ -502,7 +503,9 @@ async def _generate_async(
                     for messages in messages_list
                 ]
 
-            responses = await asyncio.gather(*tasks)
+            responses = await tqdm_asyncio.gather(
+                *tasks, desc=self.block_name, unit="req"
+            )
             return responses
 
         except Exception as e: