fix(wasm): check HTTP status before deserializing response body

[sanskar-soni-9]

What kind of change does this PR introduce?

Bug fix

What is the current behavior?

When upstream APIs reject a connection (e.g., 401 Unauthorized or 403 Forbidden) and return a non-JSON error body (such as HTML or plain text), WASM Foreign Data Wrappers fail during JSON deserialization (serde_json::from_str) with a generic error: ERROR: HV000: guest fdw error: expected value at line 1 column 1

This occurs because WASM wrappers blindly attempt to deserialize the response body into JSON before checking the HTTP status code via http::error_for_status, hiding the actual HTTP error status and response body from PostgreSQL logs.

Closes: #386

What is the new behavior?

• Ensures http::error_for_status(&resp) is checked before attempting serde_json::from_str across WASM FDWs (snowflake_fdw, cal_fdw, calendly_fdw, cfd1_fdw, notion_fdw, paddle_fdw).
• Preserves missing-object 404 logic in notion_fdw and paddle_fdw while ensuring unexpected 404 or HTTP error responses properly bubble up the HTTP status and body text.
• Enriches HTTP error mappings in snowflake_fdw polling loops so response bodies are included in error messages.

[sanskar-soni-9]

@burmecia the CI is green now - please take a look when you get a chance