fix: improve error for insufficient blob data columns

Updates the HTTP API error when the node cannot reconstruct blobs due to
"Insufficient data columns".

Changes the response from 500 Internal Server Error to 400 Bad Request
and adds a hint to run with --supernode or --semi-supernode.

Closes #8569

Author: Andrurachi

beacon_node/http_api/src/block_id.rs

@@ -483,8 +483,9 @@ impl BlockId {
                 },
             )
         } else {
-            Err(warp_utils::reject::custom_server_error(format!(
-                "Insufficient data columns to reconstruct blobs: required {num_required_columns}, but only {num_found_column_keys} were found."
+            Err(warp_utils::reject::custom_bad_request(format!(
+                "Insufficient data columns to reconstruct blobs: required {num_required_columns}, but only {num_found_column_keys} were found. \
+                You may need to run the beacon node with --supernode or --semi-supernode."
             )))
         }
     }