Update virtual environment, create new validations

- Removed langchain from virtual environment
- Updated dependencies, now on Pydantic V2
- Created new validation classes inheriting from BaseModel and ENUM
- Finished Request Body and POST requests - Pydantic pre-validators class

main_example.py

@@ -29,7 +29,7 @@ async def bands(
     band_list = [BandWithID(**b) for b in BANDS]
 
     if genre:
-        band_list = [b for b in band_list if b.genre.lower() == genre.value]
+        band_list = [b for b in band_list if b.genre.value.lower() == genre.value]
 
     if has_albums:
         band_list = [b for b in band_list if len(b.albums) > 0]