fix(cdk): Remove remediation language from generic 400 error message

The default 400 error message contained 'Please check your request
parameters' which violates the writing-good-error-messages guidelines:
- Embeds remediation language ('Please check...')
- Redundantly prefixes with 'HTTP Status Code: 400. Error:'
- Not specific enough to be actionable

Simplified to 'Bad request.' which is concise and does not embed
unhelpful remediation suggestions. Connectors should use
HttpResponseFilter with custom error_message templates to provide
API-specific context for 400 errors.

Related to airbytehq/airbyte-internal-issues#15976
Related to airbytehq/oncall#11577

Co-Authored-By: bot_apk <apk@cognition.ai>

Author: devin-ai-integration[bot]

airbyte_cdk/sources/streams/http/error_handlers/default_error_mapping.py

@@ -31,7 +31,7 @@
     400: ErrorResolution(
         response_action=ResponseAction.FAIL,
         failure_type=FailureType.system_error,
-        error_message="HTTP Status Code: 400. Error: Bad request. Please check your request parameters.",
+        error_message="Bad request.",
     ),
     401: ErrorResolution(
         response_action=ResponseAction.FAIL,

unit_tests/sources/declarative/requesters/error_handlers/test_default_error_handler.py

@@ -92,7 +92,7 @@ def test_default_error_handler_with_default_response_filter(
             ),
             ResponseAction.RETRY,
             FailureType.system_error,
-            "HTTP Status Code: 400. Error: Bad request. Please check your request parameters.",
+            "Bad request.",
         ),
         (
             "_with_http_response_status_402_fail_with_default_failure_type",