Return error message upon updating file extension `extension` field with existing one

{
  "errors" : [ {
    "message" : "duplicate key value violates unique constraint file_extensions_extension_idx_unique",
    "type" : "1",
    "code" : "-1",
    "parameters" : [ {
      "key" : "lower(f_unaccent(jsonb ->> 'extension'::text",
      "value" : ".csv"
    } ]
  } ]
}

{
  "errors" : [ {
    "message" : "fileExtension.duplication.invalid",
    "parameters" : [ ]
  } ],
  "total_records" : 1
}