fix: re-export exception classes from generated module

ariadne-codegen copies base_client.py into generated/, creating
duplicate class definitions. The generated client raises exceptions
from the generated module, so consumers must catch those exact classes.

Re-exporting from the package __init__.py ensures that
\`from deezer_python_gql import GraphQLClientGraphQLMultiError\`
gives the same class identity the client actually raises.

Author: jdaberkow

deezer_python_gql/__init__.py

@@ -1,5 +1,19 @@
 """Async typed Python client for Deezer's Pipe GraphQL API."""
 
+from deezer_python_gql.generated.base_client import (
+    GraphQLClientError,
+    GraphQLClientGraphQLError,
+    GraphQLClientGraphQLMultiError,
+    GraphQLClientHttpError,
+    GraphQLClientInvalidResponseError,
+)
 from deezer_python_gql.generated.client import DeezerGQLClient
 
-__all__ = ["DeezerGQLClient"]
+__all__ = [
+    "DeezerGQLClient",
+    "GraphQLClientError",
+    "GraphQLClientGraphQLError",
+    "GraphQLClientGraphQLMultiError",
+    "GraphQLClientHttpError",
+    "GraphQLClientInvalidResponseError",
+]