select: add MISSING operator support (#14406)

Probably not full support, but for regular checks it should work.

Fixes #14358

internal/s3select/csv/record.go

@@ -59,6 +59,7 @@ func (r *Record) Get(name string) (*sql.Value, error) {
 			}
 			return sql.FromBytes([]byte(r.csvRecord[idx])), nil
 		}
+		// TODO: Return Missing?
 		return nil, fmt.Errorf("column %v not found", name)
 	}