Add exception handling for HTTP requests in Neon_API_V2 class and update database-related methods in DatabaseResource class

neon_client/exceptions.py

@@ -0,0 +1,7 @@
+from requests.exceptions import HTTPError
+
+
+class NeonClientException(HTTPError):
+    """Base exception class for all exceptions raised by the Neon Client."""
+
+    pass