OpenAPI execute_query params

[BorisTyshkevich]

Feature Request: Improve execute_query Compatibility in Altinity MCP

Summary:
Enhance the /{jwe_token}/openapi/execute_query endpoint to accept both ClickHouse-native and braces wrapped query formats for better interoperability with different integrations.

Proposed Improvement:
Support all the following input styles:

1. JSON-style GET (current behavior):
   GET /{jwe_token}/openapi/execute_query?query={"SELECT 1"}

2. ClickHouse-style GET (new behavior):
   GET /{jwe_token}/openapi/execute_query?query=SELECT%201